OBJECTIVES: In this study, the effect of tube length and outer diameter (OD) size of hydroxylated-multi walled carbon nanotubes (OH-MWCNTs) on their uptake and toxicity was investigated in the nematode Caenorhabditis elegans using a functional mutant analysis. METHODS: The physicochemical properties of three different OH-MWCNTs were characterized. Uptake and toxicity were subsequently investigated on C. elegans exposed to MWCNTs with different ODs and tube lengths. RESULTS: The results of mutant analysis suggest that ingestion is the main route of MWCNTs uptake. We found that OH-MWCNTs with smaller ODs were more toxic than those with larger ODs, and OH-MWCNTs with shorter tube lengths were more toxic than longer counterparts to C. elegans. CONCLUSIONS: Overall the results suggest the aspect ratio affects the toxicity of MWCNTs in C. elegans. Further thorough study on the relationship between physicochemical properties and toxicity needs to be conducted for more comprehensive understanding of the uptake and toxicity of MWCNTs.
Caenorhabditis elegans* ; Caenorhabditis* ; Carbon* ; Eating ; Nanotubes, Carbon*

OBJECTIVES: In this study, the effect of tube length and outer diameter (OD) size of hydroxylated-multi walled carbon nanotubes (OH-MWCNTs) on their uptake and toxicity was investigated in the nematode Caenorhabditis elegans using a functional mutant analysis. METHODS: The physicochemical properties of three different OH-MWCNTs were characterized. Uptake and toxicity were subsequently investigated on C. elegans exposed to MWCNTs with different ODs and tube lengths. RESULTS: The results of mutant analysis suggest that ingestion is the main route of MWCNTs uptake. We found that OH-MWCNTs with smaller ODs were more toxic than those with larger ODs, and OH-MWCNTs with shorter tube lengths were more toxic than longer counterparts to C. elegans. CONCLUSIONS: Overall the results suggest the aspect ratio affects the toxicity of MWCNTs in C. elegans. Further thorough study on the relationship between physicochemical properties and toxicity needs to be conducted for more comprehensive understanding of the uptake and toxicity of MWCNTs.
Caenorhabditis elegans* ; Caenorhabditis* ; Carbon* ; Eating ; Nanotubes, Carbon*

Oxygen levels are unequal in different living geographical locations of human and related to normal physiology of health. The reduction of oxygen level in the body can lead to a variety of diseases, such as stroke caused by cerebral ischemia and hypoxia. In the recent years, many studies have elucidated the molecular and cellular mechanisms of organism response to different oxygen concentrations by using the nematode Caenorhabditis elegans (C. elegans) as model organism. C. elegans can escape hypoxia or hyperoxia and adapt to the ambient oxygen environments, and there are different response and regulation mechanisms in different degrees of hypoxia environment. In this paper, recent advances in the reaction of nematodes to different oxygen concentrations and the underlying mechanism were reviewed.
Animals ; Caenorhabditis elegans ; Caenorhabditis elegans Proteins ; Humans ; Hypoxia ; Oxygen

Background and Objectives: During infection, Reactive oxygen species (ROS) signaling is activated to protect the cells from invading microorganisms. However, a high level of ROS may also damage the host tissue. The anthocyanin delphinidin is known to have a strong antioxidant activity that protects cells from oxidative damage. This study explored the potential of crude anthocyanin extract from the fruit of Solanum melongena (Eggplant) and Delphinidin-3-glucoside in enhancing the innate immunity in Caenorhabditis elegans against Staphylococcus aureus and Klebsiella pneumoniae. Methodology: Caenorhabditis elegans was used to study innate immune response because it lacks adaptive immunity. First, the sublethal concentration of S. melongena crude anthocyanin extract (SMCAE) and Delphinidin-3-glucoside (D3G) in C. elegans was determined. The sublethal concentration of SMCAE and D3G was used to supplement the nematodes during its exposure to S. aureus and K. pneumoniae. The survival rate was then observed until day five post-L4. SMCAE and D3G were also tested for probable antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae. Results and Conclusion This study found that both SMCAE and D3G showed no inhibitory effect on the growth of the bacteria. However, both SMCAE and D3G enhanced the survival of the nematode when exposed to S. aureus and K. pneumoniae. Overall, this study indicates that the anthocyanin delphinidin in S. melongenacrude extract protected the C. elegans against S. aureus and K. pneumoniaeinfection through its antioxidant activity.
Anthocyanins ; Caenorhabditis elegans ; Klebsiella pneumoniae

Aging is the most important risk factor for human neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Pathologically, these diseases are characterized by the deposition of specific protein aggregates in neurons and glia, representing the impairment of neuronal proteostasis. However, the mechanism by which aging affects the proteostasis system and promotes protein aggregation remains largely unknown. The short lifespan and ample genetic resources of Caenorhabditis elegans (C. elegans) have made this species a favorite model organism for aging research, and the development of proteinopathy models in this organism has helped us to understand how aging processes affect protein aggregation and neurodegeneration. Here, we review the recent literature on proteinopathies in C. elegans models and discuss the insights we have gained into the mechanisms of how aging processes are integrated into the pathogenesis of various neurodegenerative diseases.
Aging ; Caenorhabditis elegans* ; Caenorhabditis* ; Humans ; Neurodegenerative Diseases ; Neuroglia ; Neurons ; Protein Aggregates ; Risk Factors

BACKGROUND: MicroRNAs (miRNAs)are a class of noncoding RNAs found in various organisms such as plants and mammals. However, most of the mRNAs regulated by miRNAs are unknown. Furthermore, miRNA targets in genomes cannot be identified by standard sequence comparison since their complementarity to the target sequence is imperfect in general. In thi s paper, we propose a kernel-based method for the efficient prediction of miRNA targets. To help in distinguishing the false positives from potentially valid targets, we elucidate the features common in experimentally confirmed targets. RESULTS: The performance of our prediction method was evaluated by five-fold cross-validation. Our method showed 0.64 and 0.98 in sensitivity and in specificity, respectively. Also, the proposed method reduced the number of false positives by half compared with TargetScan. We investigated the effect of feature sets on the classification of miRNA targets. Finally, we predicted miRNA targets for several miRNAs in the Caenorhabditis elegans (C.elegans )3'untranslated region (3'UTR) database. CONCLUSIONS: The targets predicted by the suggested method will help in validating more miRNA targets and ultimately in revealing the role of small RNAs in the regulation of genomes. Our algorithm for miRNA target site detection will be able to be improved by additional experimental-knowledge. Also, the increase of the number of confirmed targets is expected to reveal general structural features that can be used to improve their detection.
Caenorhabditis elegans* ; Caenorhabditis* ; Classification ; Genome ; Mammals ; MicroRNAs* ; RNA ; RNA, Messenger ; RNA, Untranslated ; Sensitivity and Specificity

Here in this study, we investigated the lifespan-extending effect and underlying mechanism of methanolic extract of Moringa olelifa leaves (MML) using Caenorhabditis elegans (C. elegans) model system. To define the longevity properties of MML we conducted lifespan assay and MML showed significant increase in lifespan under normal culture condition. In addition, MML elevated stress tolerance of C. elegans to endure against thermal, oxidative and osmotic stress conditions. Our data also revealed that increased activities of antioxidant enzymes and expressions of stress resistance proteins were attributed to MML-mediated enhanced stress resistance. We further investigated the involvement of MML on the aging-related factors such as growth, food intake, fertility, and motility. Interestingly, MML significantly reduced growth and egg-laying, suggesting these factors were closely linked with MML-mediated longevity. We also observed the movement of aged worms to estimate the effects of MML on the health span. Herein, MML efficiently elevated motility of aged worms, indicating MML may affect health span as well as lifespan. Our genetic analysis using knockout mutants showed that lifespan-extension activity of MML was interconnected with several genes such as skn-1, sir-2.1, daf-2, age-1 and daf-16. Based on these results, we could conclude that MML prolongs the lifespan of worms via activation of SKN-1 and SIR-2.1 and inhibition of insulin/IGF pathway, followed by DAF-16 activation.
Caenorhabditis elegans* ; Caenorhabditis* ; Eating ; Fertility ; Longevity ; Methanol ; Moringa oleifera* ; Moringa* ; Osmotic Pressure

Here in this study, we isolated 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) from Curcuma longa L. and elucidated the lifespanextending effect of PGG using Caenorhabditis elegans model system. In the present study, PGG demonstrated potent lifespan extension of worms under normal culture condition. Then, we determined the protective effects of PGG on the stress conditions such as thermal and oxidative stress. In the case of heat stress, PGG-treated worms exhibited enhanced survival rate, compared to control worms. In addition, PGG-fed worms lived longer than control worms under oxidative stress induced by paraquat. To verify the possible mechanism of PGG-mediated increased lifespan and stress resistance of worms, we investigated whether PGG might alter superoxide dismutase (SOD) activities and intracellular ROS levels. Our results showed that PGG was able to elevate SOD activities of worms and reduce intracellular ROS accumulation in a dose-dependent manner.
Caenorhabditis elegans* ; Caenorhabditis* ; Curcuma* ; Hot Temperature ; Longevity* ; Oxidative Stress ; Paraquat ; Prostaglandins G ; Superoxide Dismutase ; Survival Rate

A simple model organism Caenorhabditis elegans has contributed substantially to the fundamental researches in biology. In an era of functional genomics, nematode worm has been developed into a multi-purpose tool that can be exploited to identify disease-causing or disease-associated genes, validate potential drug targets. This, coupled with its genetic amenability, low cost experimental manipulation and compatibility with high throughput screening in an intact physiological condition, makes the model organism into an effective toolbox for drug discovery. This review shows the unique features of C. elegans, how it can play a valuable role in our understanding of the molecular mechanism of human diseases and finding drug leads in drug development process.
Animals ; Caenorhabditis elegans ; Drug Discovery ; Drug Evaluation, Preclinical

OBJECTIVE: To investigate the changes of lipid metabolism and stress response of adult C.elegans exposed to non-freezing low temperature and explore the possible mechanism. METHODS: The survival rate and activity of adult C.elegans cultured at 20℃ or 4℃ were observed.Lipid metabolism of the cultured adult C.elegans was evaluated using oil red O staining and by detecting the expressions of the genes related with lipid metabolism.The effects of low temperature exposure on stress level of adult C.elegans were evaluated using mitochondrial fluorescence staining and by detecting the expression levels of stress-related genes and antioxidant genes at both the mRNA and protein levels. RESULTS: The lifespan and activity of adult C.elegans exposed to low temperature were significantly reduced with decreased lipid accumulation (P < 0.05) and decreased expressions of genes related with fatty acid synthesis and metabolism (fat-5, fat-6, fat-7, fasn-1, nhr-49, acs-2 and aco-1;P < 0.01).Cold stress significantly increased the expressions of heat shock proteins hsp-70 and hsp16.2(P < 0.05) but lowered the number of mitochondria (P < 0.0001) and the expressions of atfs-1, sod-2, sod-3 and gpx-1(P < 0.05).Knockout of fat-5, nhr-49 or both fat-5 and fat-6 obviously enhanced the sensitivity of C.elegans to cold stress as shown by further reduced activity (P < 0.05) and reduced survival rate at 24 h (P < 0.0001) under cold stress. CONCLUSION Exposure to a low temperature at 4℃ results in lowered lipid metabolism of adult C.elegans accompanied by a decreased mitochondrial number and quality control ability, which triggers high expressions of stress-related genes and causes reduction of antioxidant capacity, thus callsing lowered activity and reduced lifespan of C.elegans.
Animals ; Antioxidants/metabolism* ; Caenorhabditis elegans ; Caenorhabditis elegans Proteins/genetics* ; Cold-Shock Response ; Lipid Metabolism ; Lipid Metabolism Disorders ; Longevity/genetics*