Barley Protein LFBEP-C1 from Lactiplantibacillus plantarum dy-1 Fermented Barley Extracts by Inhibiting Lipid Accumulation in a Caenorhabditis elegans Model

Objective This study aimed to investigate the lipid-lowering activity of LFBEP-C1 in high glucose-fed Caenorhabditis elegans(C.elegans).Methods In this study,the fermented barley protein LFBEP-C1 was prepared and tested for its potential anti-obesity effects on C.elegans.The worms were fed Escherichia coli OP50(E.coli OP50),glucose,and different concentrations of LFBEP-C1.Body size,lifespan,movement,triglyceride content,and gene expression were analyzed.The results were analyzed using ANOVA and Tukey's multiple comparison test.Results Compared with the model group,the head-swing frequency of C.elegans in the group of LFBEP-C1 at 20μg/mL increased by 33.88%,and the body-bending frequency increased by 27.09%.This indicated that LFBEP-C1 improved the locomotive ability of C.elegans.The average lifespan of C.elegans reached 13.55 days,and the body length and width of the C.elegans decreased after LFBEP-C1 intake.Additionally,LFBEP-C1 reduced the content of lipid accumulation and triglyceride levels.The expression levels of sbp-1,daf-2,and mdt-15 significantly decreased,while those of daf-16,tph-1,mod-1,and ser-4 significantly increased after LFBEP-C1 intake.Changes in these genes explain the signaling pathways that regulate lipid metabolism.Conclusion LFBEP-C1 significantly reduced lipid deposition in C.elegans fed a high-glucose diet and alleviated the adverse effects of a high-glucose diet on the development,lifespan,and exercise behavior of C.elegans.In addition,LFBEP-C1 regulated lipid metabolism mainly by mediating the expression of genes in the sterol regulatory element-binding protein,insulin,and 5-hydroxytryptamine signaling pathways.

Exploring the anti-aging effects of chlorogenic acid and the underlying mechanisms based on a Caenorhabditis elegans model

Objective:To explore the anti-aging effects of chlorogenic acid(CGA)and the underlying mechanisms based on a Caenorhabditis elegans(C.elegans)model.Methods:The anti-agingactivityofCGAwasstudied basedon thebodylength,exercisebehavior,lipofuscin content,antioxidative stress ability,swallowing frequency,body-bending frequency,and head-swinging ability of C.elegans.Through DAF-16 nuclear translocation and SOD-3-GFP fluorescence experiments,the effects of CGA on ROS levels,antioxidant enzyme activities,MDA content,mutant-strain lifespan,and anti-aging molecular signaling pathways were explored,as well as the underlying mechanisms.Results:CGA improved multiple indices of the nematode:body length was increased(all P<0.001),head-swing frequency and body-bending frequency were increased(all P<0.05),nematode longevity was prolonged(P=0.0021),lipofuscin deposition in nematodes was slowed down(all P<0.001),the chemotaxis index was improved(P=0.0012),ROS levels were reduced(all P<.001),and SOD activity and MDA content were reduced(SOD:P=0.0017 between the low-concentration group and the control group,P<.001 between the high-concentration and medium-concentration groups and the control group;MDA:P=0.0135 between the low-concentration group and the control group,and P<0.001 between the high-concentration and medium-concentration groups and the control group).In addition,CGA also activated the DAF-16 transcription factor,promoted DAF-16 nuclear translocation under oxidative stress conditions(both P<0.001 between the high-concentration and medium-concentration groups and the control group),and increased SOD-3 gene expression in nematodes(all P<0.001).Conclusion:CGA plays an anti-aging role in C.elegans.The underlying mechanisms include activation of the insulin/IGF-1 signaling pathway and enhancement of DAF-16 activity.This study lays a foundation for further research into the anti-aging effects of CGA.

The role of crm-1 in ionizing radiation-induced nervous system dysfunction in Caenorhabditis elegans

Ionizing radiation can cause changes in nervous system function.However,the underlying mechanism remains unclear.In this study,Coenorhabditis elegans(C.elegans)was irradiated with 75 Gy of ^(60)Co whole-body γ radiation.Behavioral indicators(head thrashes,touch avoidance,and foraging),and the development of dopaminergic neurons related to behavioral function,were evaluated to assess the effects of ionizing radiation on nervous system function in C.elegans.Various behaviors were impaired after whole-body irradiation and degeneration of dopamine neurons was observed.This suggests that 75 Gy of γ radiation is sufficient to induce nervous system dysfunction.The genes nhr-76 and crm-1,which are reported to be related to nervous system function in human and mouse,were screened by transcriptome sequencing and bioinformatics analysis after irradiation or sham irradiation.The expression levels of these two genes were increased after radiation.Next,RNAi technology was used to inhibit the expression of crm-1,a gene whose homologs are associated with motor neuron development in other species.Downregulation of crm-1 expression effectively alleviated the deleterious effects of ionizing radiation on head thrashes and touch avoidance.It was also found that the expression level of crm-1 was regulated by the nuclear receptor gene nhr-76.The results of this study suggest that knocking down the expression level of nhr-76 can reduce the expression level of crm-1,while down-regulating the expression level of crm-1 can alleviate behavioral disorders induced by ionizing radiation.Therefore,inhibition of crm-1 may be of interest as a potential therapeutic target for ionizing radiation-induced neurological dysfunction.

Metabolomics and gene expression levels reveal the positive effects of teaseed oil on lifespan and aging process in Caenorhabditis elegans

As an irreplaceable dietary constituent,lipids play a vital important role in health,but their effects on aging process and longevity are still not well known yet.In this paper,the metabolic profiling and gene expression levels of Caenorhabditis elegans were investigated to explore the effects of different edible oils on senescence and lifespan.The results showed that teaseed oil(TO)could prolong the life expectancy and slow down the aging process of C.elegans.Compared to the control group,the intake of lard oil(LO)and TO increased the expression levels of genes related to inhibition of protein aggregation(akt-1,daf-16,hsf-1,hsp-16.2)and lipid metabolism(daf-7,daf-1,mdt-15,lipl-4,fat-5,fat-6,fat-7),with a more significant alteration in TO group.Metabolomics revealed that palm oil can upregulated plenty of fatty acids(palmitic acid,stearic acid,tetracosanoic acid),together with some amino acids(tryptophan,L-aspartate,L-valine)and carbohydrate(D-glucose),while the trend was opposite in TO group.Besides,moderate-to-strong correlations were found between differential metabolites and changed genes.In general,this paper claimed that TO could prolong lifespan and slow down aging process via regulating the lipids,amino acids and carbohydrates metabolism.

Application of Caenorhabditis elegans in screening active ingredients of traditional Chinese medicine

People continue to recognize the important role of Chinese medicine in the treatment of diseases,and there is an urgent need to clarify the mechanism of Chinese medicine.Because of the multi-target and multi-component characteristics of traditional Chinese medicine,it is difficult to elaborate from a single perspective.As a high-quality animal model,Caenorhabditis elegans with the characteristics of small size and fast reproduction,has been widely used in traditional Chinese medicine activity experiments.In this article,Caenorhabditis elegans,as model organisms used to screen the active components of traditional Chinese medicine were reviewed.

原位杂交检测lin-28 mRNA在Caenorhabditis elegans中的分布

利用原位杂交检测了异时性基因lin-28 mRNA在野生型和lin-4,lin-14突变体以及lin-4,lin-14双突变体中的分布,发现lin-28 mRNA在胚胎和成虫生殖腺中存在.还发现lin-4突变不改变lin-28 mRNA分布,证明了lin-28表达独立于lin-4抑制通路的存在.

食细菌线虫Caenorhabditis elegans的取食偏好性

通过设置平板培养试验,以模式种线虫Caenorhabditis elegans为材料,观察了食细菌线虫的取食行为。结果表明:C.elegans在取食细菌时对原位土壤中分离的一种Pseudomonas sp细菌存在最大的取食偏好性。这种取食偏好性表现在大部分C.elegans在24 h内都直接朝Pseudomonas sp迁移,说明C.elegans能通过某种机制识别Pseudomonas sp。距离迁移试验及C.elegans迁移率表明它可能是通过辨别细菌所发出的气味识别它喜欢的食物。C.elegans的繁殖率跟其取食的偏好性是相关的,在迁移率较高的细菌培养基中线虫表现出更高的繁殖率。结果还表明:相对于G+细菌而言,C.elegans偏好取食G-细菌。为进一步了解土壤生态系统中食细菌线虫与细菌群落结构间相互关系提供了帮助。

Toxicity of Selected Imidazolium-based Ionic Liquids on Caenorhabditis elegans： a Quantitative Structure-Activity Relationship Study

Due to the large number of ionic liquids （ILs） and their potential environmental risk, assessing the toxicity of ILs by ecotoxicological experiment only is insufficient. Quantitative structure- activity relationship （QSAR） has been proven to be a quick and effective method to estimate the viscosity, melting points, and even toxicity of ILs. In this work, the LC50 values of 30 imidazolium-based ILs were determined with Caenorhabditis elegans as a model animal. Four suitable molecular descriptors were selected on the basis of genetic function approximation algorithm to construct a QSAR model with an R^2 value of 0.938. The predicted lgLC50 in this work are in agreement with the experimental values, indicating that the model has good stability and predictive ability. Our study provides a valuable model to predict the potential toxicity of ILs with different sub-structures to the environment and human health.

Learning and learning choice in the nematode Caenorhabditis elegans

The nematode Caenorhabditis elegans is an attractive model organism to study the behavioral plasticity for its simple system and ability to respond to diverse environmental stimuli, such as touch, smell, taste and temperature. Learning in C. elegans encompasses both non-associative learning and associative learning. Till now, themotaxis and chemotaxis are two major paradigms for associative learning and there are at least 6 forms of chemotaxis-mediated associative learning. Three research systems have also been explored to study the mechanism of learning choice in worms. This review will discuss the forms, research models, genetic and molecular regulation of learning and learning choice in C. elegans.

原位杂交检测lin-4 mRNA在Caenorhabditis elegans中的表达

lin-4是控制Caenorhabditis elegans(C.elegans)幼虫发育的异时性基因,也是一种小RNA分子(microRNA)。通过整体原位杂交检测小RNA lin-4在野生型和lin-14、lin-28突变体中的区域性表达,探讨lin-4在C.elegans发育时空控制中的作用。结果表明:lin-4 mRNA在胚胎发育的早期和中期表达,胚胎后期至L1期末没有表达,之后又持续表达,成虫中也可以检测到lin-4 mRNA的存在。在lin-14和lin-28突变体中,lin-4的表达基本与野生型一致,不受lin-14、lin-28基因突变的影响,说明lin-14和lin-28是lin-4的下游基因。

Multi-biological defects caused by lead exposure exhibit transferable properties from exposed parents to their progeny in Caenorhabditis elegans

Whether the multi-biological toxicity from lead exposure could be transferred to progeny has not been clarified. In the present study, we explored the Caenorhabditis elegans to analyze the multiple toxicities from lead exposure and their possibly transferable properties. The lead exposure could cause series of severe multi-biological defects with a concentration-dependent manner by affecting the endpoints of life span, development, reproduction and locomotion behaviors in nematodes. Moreover, most of these toxicities could be transferred to progeny from lead exposed animals and some of the defects in progeny appeared even more severe than in their parents, such as the body sizes and mean life spans. We summarized the defects caused by lead exposure into three groups according to their transferable properties or rescue patterns. That is, the defects caused by lead exposure could be largely, or partially, or became even more severe in progeny animals. Therefore, our results suggest that lead exposure can cause severely multi-biological defects, and most of these multiple toxicities can be considered as transferable for exposed animals in C. elegans.

Prolonged manganese exposure induces severe deficits in lifespan,development and reproduction possibly by altering oxidative stress response in Caenorhabditis elegans

We examined the possible multiple defects induced by acute and prolonged exposure to high levels of manganese（Mn） solution by monitoring the endpoints of lifespan,development,reproduction,and stress response.Our data suggest that acute exposure（6 h） to Mn did not cause severe defects of life span,development,and reproduction,similarly,no significant defect could be found in animals exposed to a low concentration of Mn（2.5 μmol/L） for 48 h.In contrast,prolonged exposure（48 h） to high Mn concentrations（75 and 200 μmol/L） resulted in significant defects of life span,development,and reproduction,as well as the increase of the percentage of population with hsp-16.2：：gfp expression indicating the obvious induction of stress responses in exposed animals.Moreover,prolonged exposure（48 h） to high concentrations（75 and 200 μmol/L） of Mn decreased the expression levels of antioxidant genes of sod-1,sod-2,sod-3,and sod-4 compared to control.Therefore,prolonged exposure to high concentrations of Mn will induce the severe defects of life span,development,and reproduction in nematodes possibly by affecting the stress response and expression of antioxidant genes in Caenorhabditis elegans.

Toxicity evaluation in a paper recycling mill effluent by coupling bioindicator of aging with the toxicity identification evaluation method in nematode Caenorhabditis elegans

Toxicity identification evaluation (TIE) can be used to determine the specific toxicant(s) in industrial effluents.In the current study,the authors have attempted to combine the advantages of the model organism,Caenorhabditis elegans,with the virtues of the TIE technique,to evaluate and identify the toxicity on aging from a paper recycling mill effluent.The results indicate that only the toxicities from mixed cellulose (MC) filtration and EDTA treatment are similar to the baseline aging toxicity,suggesting ...

Using the nematode Caenorhabditis elegans as a model animal for assessing the toxicity induced by microcystin-LR

Among more than 75 variants of microcystin （MC）, microcystin-LR （MC-LR） is one of the most common toxins. In this study, the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied. C. elegans was treated with MC-LR at different concentrations ranging from 0.1 to 80 μg/L. The results showed that MC-LR could reduce lifespan, delay development, lengthen generation time, decrease brood size, suppress locomotion behavior, and decreases hsp-16-2-gfp expression. The endpoints of generation time, brood size, and percentage of the population expressing hsp-16-2-gfp were very sensitive to 1.0μg/L of MC-LR, and would be more useful for the evaluation of MC-LR toxicity. Furthermore, the tissue-specific hsp-16-2-gfp expressions were investigated in MC-LR-exposed animals, and the nervous system and intestine were primarily affected by MC-LR. Therefore, the generation time, brood size, and hsp-16-2-gfp expression in C. elegans can be explored to serve as valuable endpoints for evaluating the potential toxicity from MC-LR exposure.

The Lifespan-Promoting Effect of Otophylloside B in Caenorhabditis elegans

Aging is the major risk factor for many human diseases and degeneration.Thus,clinically effective medicine could delay the process of aging and aging-related diseases are desperately wanted.In traditional Chinese medicine(TCM),some were claimed to slow down aging.Qingyangshen(Cynanchum otophyllum schneid)is such a TCM.Here,we assayed the longevity effect of compound Otophylloside B(Ot B),a C-21 steroidal glycoside isolated from Qingyangshen,in Caenorhabditis elegans,which is a popular model for aging research.Our results showed that Ot B could modestly extend the lifespan of C.elegans,delay the age-related decline of body movement and improve the stress resistance.Further investigating the molecular mechanism of lifespan extension effect revealed that Ot B could activate the FOXO transcription factor DAF-16.Ot B could not further extend the lifespan of long-lived mutant of insulin/IGF-1-like receptor(daf-2).In addition,Ot B also requires SIR-2.1 and CLK-1 which is an enzyme in ubiquinone synthesis,for lifespan extension.

Adverse effects of metal exposure on chemotaxis towards water-soluble attractants regulated mainly by ASE sensory neuron in nematode Caenorhabditis elegans

Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed in animals exposed to 150 μmol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble attractants in Pb exposed che-1 mutant at concentrations more than 2.5 μmol/L, and in Cu, Ag, and Cr exposed che-1 mutant at concentrations more than 50 μmol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes.

Evaluation of the long-term memory for thermosensation regulated by neuronal calcium sensor-1 in Caenorhabditis elegans

Objective To evaluate whether the thermotaxis tracking model is suitable for assessing long-term memory （LTM） in the nematode Caenorhabditis elegans. Methods Animals were trained at 20℃ overnight in presence of food. The percentage of animals performing isothermal tracking （IT） behavior was measured at different time intervals after the training. Results The percentage of animals performing IT behavior, the numbers of body bends inside and outside the training temperature, and the expression patterns of AFD and AIY neurons were similar to those in control animals at 36 and 48 h after training; whereas when extending to 60, 72, and 84 h, locomotory behavior defects were observed in the assayed animals, suggesting that this thermal tracking model is feasible for analyzing LTM at 36 and 48 h after training. Moreover, the percent-age of animals performing IT behavior was reduced at 18, 36, and 48 h after training in neuronal calcium sensor-1 gene （nsc-1） mutant animals compared with that in wild-type N2 animals. In addition, exposure to plumbum （Pb） significantly repressed the LTM at 18, 36, and 48 h after training in both wild-type N2 and ncs-1 mutant animals. Conclusion The thermotaxis tracking model is suitable for evaluating the LTM regulated by NCS-1, and can be employed for elucidating regulatory functions of specific genes or effects of stimuli on memory in C. elegans.

Induction of chemotaxis to sodium chloride and diacetyl and thermotaxis defects by microcystin-LR exposure in nematode Caenorhabditis elegans

Apart from the liver disruption, embryotoxicity and genotoxicity, microcystin （MC）-LR also could cause neurotoxicity. Nematode Caenorhabditis elegans was explored as a model to study the neurotoxicity. In the present study, we provided evidence to indicate the neurotoxicity on chemotaxis to NaCl and diacetyl, and thermotaxis from MC-LR exposure to C. elegans. As a result, higher concentrations of MC-LR caused significantly severe defects of chemotaxis to NaCl and diacetyl, and thermotaxis. The neurotoxicity on chemotaxis to NaCl and diacetyl, and thermotaxis from MC-LR exposure might be largely mediated by the damage on the corresponding sensory neurons （ASE, AWA, and AFD） and interneuron AIY. The expression levels ofche-1 and odr-7 were significantly decreased （P 〈 0.01） in animals exposed to MC-LR at concentrations lower than 10 μg/L, whereas the expression levels of ttx-1 and ttx-3 could be significantly （P 〈 0.01） lowered in animals even exposed to 1 μg/L of MC-LR. Moreover, both the chemotaxis to NaCl and diacetyl and the thermotaxis were more significantly reduced in MC-LR exposed mutants of che-1（p674）, odr-7（ky4）, ttx-1（p767）, and ttx-3（ks5） than those in exposed wild-type N2 animals at the same concentrations.

Otophylloside B Protects Against AβToxicity in Caenorhabditis elegans Models of Alzheimer’s Disease

Alzheimer’s disease(AD)is a major public health concern worldwide and the few drugs currently available only treat the symptoms.Hence,there is a strong need to find more effective anti-AD agents.Cynanchum otophyllum is a traditional Chinese medicine for treating epilepsy,and otophylloside B(Ot B),isolated from C.otophyllum,is the essential active component.Having previously identified anti-aging effects of Ot B,we evaluated Ot B for AD prevention in C.elegant models of AD and found that Ot B extended lifespan,increased heat stress-resistance,delayed body paralysis,and increased the chemotaxis response.Collectively,these results indicated thatOt B protects against Aβtoxicity.Further mechanistic studies revealed that Ot B decreased Aβdeposition by decreasing the expression of Aβat the mRNA level.Genetic analyses showed that Ot B mediated its effects by increasing the activity of heat shock transcription factor(HSF)by upregulating the expression of hsf-1 and its target genes,hsp-12.6,hsp-16.2 and hsp-70.Ot B also increased the expression of sod-3 by partially activating DAF-16,while SKN-1 was not essential in Ot B-mediated protection against Aβtoxicity.

Toxicity of Sodium Fluoride to Caenorhabditis elegans

Objective To investigate the toxic effect of sodium fluoride（NaF） on the nematode Caenorhabditis elegans（C.elegans）.Methods Adult C.elegans were exposed to different concentrations of NaF（0.038 mmol/L,0.38 mmol/L,and 3.8 mmol/L） for 24 h.To assess the physiological effects of NaF,the brood size,life span,head thrashes,and body bend frequency were examined.Reactive oxygen species（ROS） and cell apoptosis were detected as parameters of biochemical response.The gene expressions were determined by real‐time polymerase chain reaction（PCR） to assess the molecular‐level response.Results At the physiological level,the brood size of C.elegans exposed to 0.038 mmol/L,0.38 mmol/L,and 3.8 mmol/L concentrations of NaF were reduced by 6%,26%,and 28% respectively in comparison with the control group.The maximum life spans of C.elegans exposed to 0.038 mmol/L,0.38 mmol/L,and 3.8 mmol/L concentrations of NaF were reduced by 3 days and 5 days,respectively.Head thrashes and body bend frequency both decreased with increasing concentrations of NaF.At the biochemical level,the production of ROS and the incidence of cell apoptosis increased with increasing concentrations of NaF（P0.05）.At the molecular level,different concentrations of NaF exposure raised the expression of stress‐related genes,such as hsp16.1,sod‐3,ctl‐2,dhs‐28,gst‐1,and cep‐1.Conclusion NaF exposure could induce multiple biological toxicities to C.elegans in a concentration‐dependent manner.These toxicities may be relevant to the oxidative stress induced by increased ROS production and accumulation in C.elegans.