Nanoplastics are emerging contaminants that may co-exist with organochlorine pesticides and adversely affect invertebrates in the environment.However,the impact of environmental aging on the combined toxicity of nanop...Nanoplastics are emerging contaminants that may co-exist with organochlorine pesticides and adversely affect invertebrates in the environment.However,the impact of environmental aging on the combined toxicity of nanoplastics and organochlorine pesticides remains unclear.This study investigated the effects of aging on the combined toxicity of polystyrene nanoplastics(PS NPs)and chlordane against Caenorhabditis elegans.The results showed that photo-aging altered the physicochemical properties of PS NPs and promoted the combined toxicity of PS NPs and chlordane to nematodes by reducing survival rate,body length and enhancing germline apoptosis.Additionally,combined exposure of nematodes to aged PS NPs and chlordane significantly increased reactive oxygen species production and intestinal permeability,suggesting that aging enhances combined toxicity through oxidative stress and intestinal damage.Moreover,aging increased chlordane contents in nematodes without promoting PS NPs accumulation,potentially leading to increased combined toxicity of PS NPs and chlordane.Notably,aging significantly increased the accumulation of PS NPs in the posterior intestine of the nematode during co-exposure,which may be responsible for the most sensitive and highest degree of change in germline apoptosis.These observations emphasize the significance of accounting for environmental aging as well as the accumulation and distribution of nanoplastics in organisms when assessing the combined effects of nanoplastics and coexisting pollutants.展开更多
A class of persistent organic pollutants,polychlorinated biphenyls(PCBs),are ubiquitous in the environment and human tissues which are continuously and long-term threatened.We aim to investigate the toxic effects and ...A class of persistent organic pollutants,polychlorinated biphenyls(PCBs),are ubiquitous in the environment and human tissues which are continuously and long-term threatened.We aim to investigate the toxic effects and the underlying mechanisms of PCB153 using Caenorhabditis elegans as a model organism.Our findings demonstrated that exposure to an optimized concentration of 2μmol/L PCB153 had adverse effects on C.elegans,led to reduction of lifespan,body length,frequency of body bending,and head wiggling.Additionally,this exposure led to an increase in the accumulation of reactive oxygen species,superoxide dismutase,lipofuscin and fat content within the organism.Furthermore,gene set enrichment analysis and whole transcriptome sequencing revealed,a significant up-regulation of Cytochrome P450(CYP)family genes,which are crucial for the xenobiotics metabolism in C.elegans.Knocking down specific genes within the CYPs family,including cyp-35C1,cyp-35A5,cyp-35A3,cyp-34A1,and cyp-34A10,via RNA interference were able to reverse the shortening of lifespan and fat accumulation induced by PCB153 exposure.Moreover,a comprehensive a competing endogenous RNA network was constructed by integrating qPCR-validated differentially expressed m RNA along with lncRNA,circRNA,and miRNA identified by transcriptomic sequencing.This study emphasizes that PCB153 exposure leads to the physiological impairments,particularly fat accumulation and a shorter lifespan,through the modulation of CYP450 family genes.These findings contribute to our understanding of environmental pollutants and their impact on biological systems and provide valuable information on the toxic effects and potential risks associated with PCB153 exposure.展开更多
BACKGROUND Neurodegeneration refers to the progressive loss of neurons,affecting both their structure and function.It is driven by synaptic dysfunction,disruptions in neural networks,and the accumulation of abnormal p...BACKGROUND Neurodegeneration refers to the progressive loss of neurons,affecting both their structure and function.It is driven by synaptic dysfunction,disruptions in neural networks,and the accumulation of abnormal protein variants.Endoplasmic reticulum(ER)stress,caused by the accumulation of misfolded or unfolded protein,is a major contributor to neurodegeneration.Dithiothreitol(DTT)is a widely used redox reagent that disrupts the oxidative protein folding environment,inducing ER stress and leading to the imbalance in protein homeostasis can activate stress response pathway,potentially contributing to neurodegenerative processes.Caenorhabditis elegans(C.elegans)is a widely used model organism for studying neurodegeneration due to its well-mapped nervous system,approximately onethird of neuron cells in their body,complete genome sequenced,and conserved stress response pathway.AIM To study the neurodegeneration in C.elegans caused by DTT-induced ER stress,assessed by behavioral,molecular,and lifespan changes.METHODS C.elegans were cultured on nematode growth medium plates with OP50,and ER stress was induced using DTT.Effects were assessed via behavioral assays such as locomotion,chemotaxis,lifespan assay,and molecular studies.RESULTS DTT exposure led to a significant decline in locomotion and chemotaxis response,indicating neurotoxicity.A reduction in lifespan was observed,suggesting an overall impact on health.Molecular analysis confirmed ER stress activation.DTT-induced ER stress negatively affects C.elegans,leading to behavioral impairments and molecular alterations associated with neurodegeneration.CONCLUSION These findings establish C.elegans as a potential model for studying ER stress-mediated neurotoxicity and its implications in neurodegenerative diseases.展开更多
In the current study,the Zygomycetes fungus Cunninghamella elegans NRRL Y-1392 was evaluated for its ability to grow in extracts derived from dried and ground agricultural residues,such as mushroom stalks and roots fr...In the current study,the Zygomycetes fungus Cunninghamella elegans NRRL Y-1392 was evaluated for its ability to grow in extracts derived from dried and ground agricultural residues,such as mushroom stalks and roots from hydroponically cultivated lettuces and produce poly-unsaturated fatty acids(PUFA)andγ-linolenic acid(GLA)rich lipids.Initially,the compositions of stalks and lettuce roots were analysed,and the fungus was batch-flask cultivated on six different commercial semi-defined substrates containing different sugars detected in stalks and roots to evaluate its catabolic ability.C.elegans was capable to assimilate all sugars,but at a lower rate in the case of arabinose.Subsequently,C.elegans was cultivated on tailor-made semi-defined commercial substrates,resembling hydrolysates containing carbohydrates found in mushroom stalks,under both nitrogen-excess and nitrogen-limited conditions,and resembling that of hydrolysates of roots,under nitrogen-excess conditions.Based on the results,under nitrogen-excess conditions,in the case of media resembling stalks hydrolysates,higher production values for biomass,PUFAs,and GLA were observed(20.3 g/L,1906 mg/L,668 mg/L),accompanied by high productivity values due to short cultivation periods,while under nitrogen limitation,high lipid accumulation(lipid in dry cell weight=48%,w/w)was presented,and lipids rich in oleic acid were produced.Finally,the fungus was cultivated on a medium derived from hot water-extraction applied to mush-room stalks,enriched with organic nitrogen sources.The fungus was successfully grown on the sugar-rich waterextract derived from mushroom stalks,resulting in dry biomass of 14.5 g/L,lipids of 1.8 g/L,with 15%(w/w)of GLA in cellular lipids.展开更多
4-Nitrophenol(4-NP),as a toxic and refractory pollutant,has generated significant concern due to its adverse effects.However,the potential toxic effects andmechanism remained unclear.In this study,the reproduction,dev...4-Nitrophenol(4-NP),as a toxic and refractory pollutant,has generated significant concern due to its adverse effects.However,the potential toxic effects andmechanism remained unclear.In this study,the reproduction,development,locomotion and reactive oxygen species(ROS)production of Caenorhabditis elegans were investigated to evaluate the 4-NP toxicity.We used metabolomics to assess the potential damage mechanisms.The role of metabolites in mediating the relationship between 4-NP and phenotypes was examined by correlation and mediation analysis.4-NP(8 ng/L and 8μg/L)caused significant reduction of brood size,ovulation rate,total germ cells numbers,head thrashes and body bends,and an increase in ROS.However,the oosperm numbers in uterus,body length and body width were decreased in 8μg/L.Moreover,36 differential metabolites were enriched in the significant metabolic pathways,including lysine biosynthesis,β-alanine metabolism,tryptophan metabolism,pentose phosphate pathway,pentose and glucuronate interconversions,amino sugar and nucleotide sugar metabolism,starch and sucrose metabolism,galactose metabolism,propanoate metabolism,glycerolipid metabolism,and estrogen signaling pathway.The mechanism of 4-NP toxicity was that oxidative stress caused by the perturbation of amino acid,which had effects on energy metabolism through disturbing carbohydrate and lipid metabolism,and finally affected the estrogen signaling pathway to exert toxic effects.Moreover,correlation and mediation analysis showed glycerol-3P,glucosamine-6P,glucosamine-1P,UDP-galactose,L-aspartic acid,and uracilwere potential markers for the reproduction and glucose-1,6P2 for developmental toxicity.The results provided insight into the pathways involved in the toxic effects caused by 4-NP and developed potential biomarkers to evaluate 4-NP toxicity.展开更多
Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibit...Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibitory sensory stimuli was modulated by changing the metal ion barrier.Moreover,the hen-1,ttx-3 and casy-1 mutants having known defects in integrative response were used to evaluate the modulated assay systems.Based on the examined assay systems,new genes possibly involved in the sensory integration control were identified.Results In the presence of different metal ion barriers and diacetyl,locomotion behaviors,basic movements,pan-neuronal,cholinergic and GABAergic neuronal GFP expressions,neuronal development,structures of sensory neurons and interneurons,and stress response of nematodes in different regions of examined assay systems were normal,and chemotaxis toward different concentrations of diacetyl and avoidance of different concentrations of metal ions were inhibited.In the first group,most of the nematodes moved to diacetyl by crossing the barrier of Fe2＋,Zn2＋,or Mn2＋.In the second group,almost half of the nematodes moved to diacetyl by crossing the barrier of Ag＋,Cu2＋,Cr2＋,or Cd2＋.In the third group,only a small number of nematodes moved to diacetyl by crossing the barrier of Pb2＋ or Hg2＋.Moreover,when nematodes encountered different metal ion barriers during migration toward diacetyl,the percentage of nematodes moving back and then turning and that of nematodes moving straight to diacetyl were very different.With the aid of examined assay systems,it was found that mutations of fsn-1 that encodes a F-box protein,and its target scd-2 that encodes a receptor tyrosine kinase,caused severe defects in integrative response,and the sensory integration defects of fsn-1 mutants were obviously inhibited by scd-2 mutation.Conclusion Based on the nematode behaviors in examined assay systems,3 groups of assay systems were obtained.The first group may be helpful in evaluating or identifying the very subtle deficits in sensory integration,and the third group may be useful for the final confirmation of sensory integration defects of mutants identified in the first or the second group of assay systems.Furthermore,the important association of sensory integration regulation with stabilization or destabilization of synaptic differentiation may exist in C.elegans.展开更多
Objective To examine the important roles of microRNAs （miRNAs） in regulating amphid structure and function, we performed a computational analysis for the genetic loci required for the sensory perception and their po...Objective To examine the important roles of microRNAs （miRNAs） in regulating amphid structure and function, we performed a computational analysis for the genetic loci required for the sensory perception and their possibly corresponding miRNAs in C. elegans. Methods Total 55 genetic loci required for the amphid structure and function were selected. Sequence alignment was combined with E value evaluation to investigate and identify the possible corresponding miRNAs. Results Total 30 genes among the 55 genetic loci selected have their possible corresponding regulatory miRNA（s）, and identified genes participate in the regulation of almost all aspects of amphid structure and function. In addition, our data suggest that both the amphid structure and the amphid functions might be regulated by a series of network signaling pathways. Moreover, the distribution of miRNAs along the 3＇ untranslated region （UTR） of these 30 genes exhibits different patterns. Conclusion We present the possible miRNA-mediated signaling pathways involved in the regulation of chemosensation and thermosensation by controlling the corresponding sensory neuron and interneuron functions. Our work will be useful for better understanding of the miRNA-mediated control of the chemotaxis and thermotaxis in C. elegans.展开更多
Objective To investigate whether genes required for synaptogenesis and synaptic function are also involved in fat storage control in Caenorhabditis elegans. Methods Fat storage was examined in mutants of genes affecti...Objective To investigate whether genes required for synaptogenesis and synaptic function are also involved in fat storage control in Caenorhabditis elegans. Methods Fat storage was examined in mutants of genes affecting the synaptogenesis and synaptic function. In addition, the genetic interactions of SNAREs syntaxin/unc-64 and SNAP-25/ric-4 with daf-2, daf-7, nhr-49, sbp-1 and mdt-15 in regulating fat storage were further investigated. The tissue-specific activities of unc-64 and ric-4 were investigated to study the roles of unc-64 and ric-4 in regulating fat storage in the nervous system and/or the intestine. Results Mutations of genes required for the formation of presynaptic neurotransmission site did not obviously influence fat storage. However, among the genes required for synaptic function, the plasma membrane-associated SNAREs syntaxin/unc-64 and SNAP-25/ric-4 genes were involved in the fat storage control. Fat storage in the intestinal cells was dramatically increased in unc-64 and ric-4 mutants as revealed by Sudan Black and Nile Red strainings, although the fat droplet size was not significantly changed. Moreover, in both the nervous system and the intestine, expression of unc-64 significantly inhibited the increase in fat storage observed in unc-64 mutant. And expression of ric-4 in the nervous system completely restored fat storage in ric-4 mutant. Genetic interaction assay further indicated that both unc-64 and ric-4 regulated fat storage independently of daf-2 [encoding an insulin-like growth factor-I （IGF-I） receptor], daf-7 [encoding a transforming growth factor-β （TGF-β） ligand], and nhr-49 （encoding a nuclear hormone receptor）. Besides, mutation of daf-16 did not obviously affect the phenotype of increased fat storage in unc-64 or ric-4 mutant. Furthermore, unc-64 and ric-4 regulated fat storage probably through the ARC105/mdt-15- and SREBP/sbp-1-mediated signaling pathways. In addition, fat storage in unc-64; ric-4 was higher than that in either unc-64 or ric-4 single mutant nematodes, suggesting that unc-64 functions in parallel with ric-4 in regulating fat storage. Conclusion The plasma membrane-associated SNAREs syntaxin/ unc-64 and SNAP-25/ric-4 function in parallel in regulating fat storage in C. elegans, probably through the ARC105/mdt-15- and SREBP/sbp-1-mediated signaling pathways.展开更多
Objective To investigate the interaction between the genes required for the functions of AWA olfactory neuron and insulin/IGF signaling in regulating the longevity of nematode Caenorhabditis elegans （C. elegans）. Me...Objective To investigate the interaction between the genes required for the functions of AWA olfactory neuron and insulin/IGF signaling in regulating the longevity of nematode Caenorhabditis elegans （C. elegans）. Methods The mutants that had loss-of-function mutation of the genes required for AWA, AWC, ASE, and AFD sensory neurons were employed. Lifespan, the speed of pharynx pumping, the intestinal autofluorescence, the dauer formation, and the brood size were examined. Rescue experiments were performed to confrm the role of the genes required for the functions of AWA neuron in regulating lifespan. Moreover, genetic interactions between genes required for the functions of AWA neuron and insulin/ IGF signaling were investigated. Results Mutations of odr-7, odr-2, and odr-3 genes required for the functions of AWA neuron significantly increased the mean lifespan of nematodes and slowed the accumulation of intestinal autofluorescence. Besides, these mutations were closely associated with higher pumping rates during aging. However, mutation of odr-7, odr- 2, or odr-3 did not obviously affect the brood size or the dauer formation, and the regulation of longevity by odr-7, odr-2, and odr-3 was temperature-independent. In contrast, mutations of genes required for the functions of ASE, AWC, and AFD sensory neurons did not infuence the nematode lifespan. Moreover, expression of odr-7, odr-2 and odr-3 in AWA neuron could completely or largely restore the altered lifespan in odr-7, odr-2 and odr-3 mutants. Furthermore, genetic interaction assay demonstrated that the extended lifespan in odr-7 mutant could be suppressed by daf-16 mutation and enhanced by daf- 2 or age-1 mutation, whereas mev-1 and pha-4 were not required for the long lifespan of odr-7 mutant. Conclusion The genes required for the function of AWA sensory neuron could regulate the nematode longevity in an insulin/IGF signaling-dependent fashion in C. elegans.展开更多
Objective To identify new genes required for neurosecretory control of aging in C. elegans. Methods In view of the importance of nervous system in aging regulation, we performed the screen for genes involved in the ag...Objective To identify new genes required for neurosecretory control of aging in C. elegans. Methods In view of the importance of nervous system in aging regulation, we performed the screen for genes involved in the aging regulation from genetic loci encoding synaptic proteins by lifespan assay and accumulation of lipofuscin autofluorescence. We further investigated the dauer formation phenotypes of their corresponding mutants and whether they were possibly up-regulated by the insulin-like signaling pathway. Results The genetic loci of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd- 2, snb-1, ric-4, nrx-1, unc-13, sbt-1 and unc-64 might be involved in the aging control. In addition, functions of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd-2, snb-1, ric-4 and nrx-1 in regulating aging may be opposite to those of unc-13, sbt-1 and unc-64. The intestinal autofluorescence assay further indicated that the identified long-lived and short-lived mutants were actually due to the suppressed or accelerated aging. Among the identified genes, syd-2, hlb-1, mkk-4, scd-2, snb-1, ric-4 and unc-64 were also involved in the control of dauer formation. Moreover, daf-2 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, ric-4, sbt-1, rpm-1, unc-10, dlk- 1 and unc-13. The daf-16 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, sbt-1, rpm-1, unc-10, dlk-1 and unc-13. Conclusion These data suggest the possibly important status of the synaptic transmission to the animal＇ s life-span control machinery, as well as the dauer formation control.展开更多
Objective To study the role of HLB-1 in regulating the organization and function of neuromuscular junctions in nematode Caenorhabditis elegans. Methods To evaluate the functions of HLB-1 in regulating the organization...Objective To study the role of HLB-1 in regulating the organization and function of neuromuscular junctions in nematode Caenorhabditis elegans. Methods To evaluate the functions of HLB-1 in regulating the organization and function of neuromuscular junctions, effects of hlb-1 mutation on the synaptic structures were revealed by uncovering the expression patterns of SNB-1 ：：GFP and UNC-49：GFP, and pharmacologic assays with aldicarb and levamisole were also used to test the synaptic functions. Further rescue and mosaic analysis confirmed HLB-1＇s role in regulating the organization and function of neuromuscular junctions. Results Loss of HLB-1 function did not result in defects in neuronal outgrowth or neuronal loss, but caused obvious defects of SNB-1：：GFP and UNC-49：：GFP puncta localization, suggesting the altered presynaptic and postsynaptic structures. The mutant animals exhibited severe defects in locomotion behaviors and altered responses to an inhibitor of acetylcholinesterase and a cholinergic agonist, indicating the altered presynaptic and postsynaptic functions. Rescue and mosaic analysis experiments suggested that HLB-1 regulated synaptic functions in a cell nonautonomously way. Moreover, HLB- 1 expression was not required for the presynaptic active zone morphology. Genetic evidence further demonstrated that hlb-1 acted in a parallel pathway with syd-2 to regulate the synaptic functions. Conclusion HLB-1 appeared as a new regulator for the organization and function of neuromuscular junctions in C. elegans.展开更多
Objective To screen and identify genetic loci affecting the active zone formation in C. elegans. Methods A SYD-2：：GFP reporter was constructed and used as an active zone marker for forward genetic screen to identify...Objective To screen and identify genetic loci affecting the active zone formation in C. elegans. Methods A SYD-2：：GFP reporter was constructed and used as an active zone marker for forward genetic screen to identify genetic loci affecting the active zone formation. Results Eight isolated mutant alleles were characterized from 15,000 haploid genomes. The SYD-2：：GFP phenotypes of these mutants are mainly reflected as the changes of number, morphology, distribution of puncta and the gaps appearance. Some mutants also exhibit visible behavioral or physical phenotypes, and aldicarb resistant or sensitive phenotypes. Conclusion These mutants provide the opportunity for further systematic research on the active zone formation and the neurotransmission.展开更多
Objective To investigate the role of environmental factor—temperature in the regulation of aging process by unc-13 and sbt-1 in Caenorhabditis elegans. Methods The lifespan, the speed of pharynx pumping, and the inte...Objective To investigate the role of environmental factor—temperature in the regulation of aging process by unc-13 and sbt-1 in Caenorhabditis elegans. Methods The lifespan, the speed of pharynx pumping, and the intestinal autofluorescence of unc-13 and sbt-1 mutants were examined at different temperature conditions. In addition, to exclude the possible influences from other factors in unc-13 and sbt-1 mutants, the dauer formation, the thermotaxis, the brood size and the population percentage of the mutants expressing hsp16.2-gfp were further investigated. Results Mutations of unc-13 and sbt-1 significantly increased the mean and the maximum lifespans of nematodes cultured at 20 oC and 25 oC, while no noticeable increase was found at 15 oC in either the mean or the maximum lifespan. Investigations on the speed of pharynx pumping and the intestinal autofluorescence suggested that at 20 oC and 25 oC, mutations of unc-13 and sbt-1 could slow the aging process and delay the accumulation of aging-related cellular damage. Meanwhile, mutations of unc-13 or sbt-1 did not affect the dauer formation or the thermotaxis to different temperatures in nematodes. In contrast, at 20 oC and 25 oC conditions, mutations of unc-13 and sbt-1 significantly decreased the brood size and the percentage of nematodes expressing hsp16.2-gfp, while no such differences were detected at 15 oC. Moreover, the thermotolerance of unc-13 and sbt-1 mutants could be greatly strengthened after the 16-h heat shock at 35 oC. Conclusion The regulation of aging by unc-13 and sbt-1 is temperature-dependent. And the alterations in reproduction capability and stress response may be associated with the formation of this temperature-dependent property.展开更多
Objective To investigate the toxic effect of environmental neurotoxin MPP^＋ to C.elegans and identify the mechanisms that cause the toxicity.Methods Humanα-synuclein transgenic C.elegans was used as the animal model...Objective To investigate the toxic effect of environmental neurotoxin MPP^＋ to C.elegans and identify the mechanisms that cause the toxicity.Methods Humanα-synuclein transgenic C.elegans was used as the animal model,the toxic effect of MPP^＋ to dopamine（DA）neurons and the lifespan of worms was tested.The worms were feed with OP50 to determine whether ATP increase can rescue the worm from toxicity.ATP level and aberrant protein accumulation were analyzed in the MPP^＋ treated worms with or without OP50 addition.Results We found that MPP^＋ induced DA cell death and worm lethality,which could be prevented by OP50 treatment.OP50 exerted the protective effect by up-regulating ATP level,even though it also induced accumulation ofα-synuclein.Despite the undefined role of protein aggregation to the cell death,our results showed that the toxicity of MPP^＋ was mainly caused by the ATP depletion in theα-synuclein transgenic C.elegans.Conclusion MPP^＋ could induce DA neuronal death and worm lethality inα-synuclein transgenic C.elegans;Compared with the aggregation ofα-synuclein,the major cause of MPP^＋ toxicity appeared due to ATP depletion.展开更多
基金supported by the National Key Research and Development Program of China(No.2020YFC1808204)the National Natural Science Foundation of China(Nos.22206001 and U22A20406)the Scientific Research Foundation of Education Department of Anhui Province of China(No.KJ2021A0074).
文摘Nanoplastics are emerging contaminants that may co-exist with organochlorine pesticides and adversely affect invertebrates in the environment.However,the impact of environmental aging on the combined toxicity of nanoplastics and organochlorine pesticides remains unclear.This study investigated the effects of aging on the combined toxicity of polystyrene nanoplastics(PS NPs)and chlordane against Caenorhabditis elegans.The results showed that photo-aging altered the physicochemical properties of PS NPs and promoted the combined toxicity of PS NPs and chlordane to nematodes by reducing survival rate,body length and enhancing germline apoptosis.Additionally,combined exposure of nematodes to aged PS NPs and chlordane significantly increased reactive oxygen species production and intestinal permeability,suggesting that aging enhances combined toxicity through oxidative stress and intestinal damage.Moreover,aging increased chlordane contents in nematodes without promoting PS NPs accumulation,potentially leading to increased combined toxicity of PS NPs and chlordane.Notably,aging significantly increased the accumulation of PS NPs in the posterior intestine of the nematode during co-exposure,which may be responsible for the most sensitive and highest degree of change in germline apoptosis.These observations emphasize the significance of accounting for environmental aging as well as the accumulation and distribution of nanoplastics in organisms when assessing the combined effects of nanoplastics and coexisting pollutants.
基金supported by the National Natural Science Foundation of China(No.81872584)the Natural Science Foundation of Shenzhen(No.JCYJ20210324093211030)+1 种基金Henan Province’s Key R&D and Promotion Projects(No.252102310075)the Interdisciplinary Research for Firstclass Discipline Construction Project of Henan University(No.2019YLXKJC04)。
文摘A class of persistent organic pollutants,polychlorinated biphenyls(PCBs),are ubiquitous in the environment and human tissues which are continuously and long-term threatened.We aim to investigate the toxic effects and the underlying mechanisms of PCB153 using Caenorhabditis elegans as a model organism.Our findings demonstrated that exposure to an optimized concentration of 2μmol/L PCB153 had adverse effects on C.elegans,led to reduction of lifespan,body length,frequency of body bending,and head wiggling.Additionally,this exposure led to an increase in the accumulation of reactive oxygen species,superoxide dismutase,lipofuscin and fat content within the organism.Furthermore,gene set enrichment analysis and whole transcriptome sequencing revealed,a significant up-regulation of Cytochrome P450(CYP)family genes,which are crucial for the xenobiotics metabolism in C.elegans.Knocking down specific genes within the CYPs family,including cyp-35C1,cyp-35A5,cyp-35A3,cyp-34A1,and cyp-34A10,via RNA interference were able to reverse the shortening of lifespan and fat accumulation induced by PCB153 exposure.Moreover,a comprehensive a competing endogenous RNA network was constructed by integrating qPCR-validated differentially expressed m RNA along with lncRNA,circRNA,and miRNA identified by transcriptomic sequencing.This study emphasizes that PCB153 exposure leads to the physiological impairments,particularly fat accumulation and a shorter lifespan,through the modulation of CYP450 family genes.These findings contribute to our understanding of environmental pollutants and their impact on biological systems and provide valuable information on the toxic effects and potential risks associated with PCB153 exposure.
文摘BACKGROUND Neurodegeneration refers to the progressive loss of neurons,affecting both their structure and function.It is driven by synaptic dysfunction,disruptions in neural networks,and the accumulation of abnormal protein variants.Endoplasmic reticulum(ER)stress,caused by the accumulation of misfolded or unfolded protein,is a major contributor to neurodegeneration.Dithiothreitol(DTT)is a widely used redox reagent that disrupts the oxidative protein folding environment,inducing ER stress and leading to the imbalance in protein homeostasis can activate stress response pathway,potentially contributing to neurodegenerative processes.Caenorhabditis elegans(C.elegans)is a widely used model organism for studying neurodegeneration due to its well-mapped nervous system,approximately onethird of neuron cells in their body,complete genome sequenced,and conserved stress response pathway.AIM To study the neurodegeneration in C.elegans caused by DTT-induced ER stress,assessed by behavioral,molecular,and lifespan changes.METHODS C.elegans were cultured on nematode growth medium plates with OP50,and ER stress was induced using DTT.Effects were assessed via behavioral assays such as locomotion,chemotaxis,lifespan assay,and molecular studies.RESULTS DTT exposure led to a significant decline in locomotion and chemotaxis response,indicating neurotoxicity.A reduction in lifespan was observed,suggesting an overall impact on health.Molecular analysis confirmed ER stress activation.DTT-induced ER stress negatively affects C.elegans,leading to behavioral impairments and molecular alterations associated with neurodegeneration.CONCLUSION These findings establish C.elegans as a potential model for studying ER stress-mediated neurotoxicity and its implications in neurodegenerative diseases.
基金funded within the framework of the Project Operational Program“Research and Innovation synergies in the Attica region”,project code:ATTP4-0339570,MIS 5185063,acronym“Residues2value”by the Hellenic Republic and the European Union.
文摘In the current study,the Zygomycetes fungus Cunninghamella elegans NRRL Y-1392 was evaluated for its ability to grow in extracts derived from dried and ground agricultural residues,such as mushroom stalks and roots from hydroponically cultivated lettuces and produce poly-unsaturated fatty acids(PUFA)andγ-linolenic acid(GLA)rich lipids.Initially,the compositions of stalks and lettuce roots were analysed,and the fungus was batch-flask cultivated on six different commercial semi-defined substrates containing different sugars detected in stalks and roots to evaluate its catabolic ability.C.elegans was capable to assimilate all sugars,but at a lower rate in the case of arabinose.Subsequently,C.elegans was cultivated on tailor-made semi-defined commercial substrates,resembling hydrolysates containing carbohydrates found in mushroom stalks,under both nitrogen-excess and nitrogen-limited conditions,and resembling that of hydrolysates of roots,under nitrogen-excess conditions.Based on the results,under nitrogen-excess conditions,in the case of media resembling stalks hydrolysates,higher production values for biomass,PUFAs,and GLA were observed(20.3 g/L,1906 mg/L,668 mg/L),accompanied by high productivity values due to short cultivation periods,while under nitrogen limitation,high lipid accumulation(lipid in dry cell weight=48%,w/w)was presented,and lipids rich in oleic acid were produced.Finally,the fungus was cultivated on a medium derived from hot water-extraction applied to mush-room stalks,enriched with organic nitrogen sources.The fungus was successfully grown on the sugar-rich waterextract derived from mushroom stalks,resulting in dry biomass of 14.5 g/L,lipids of 1.8 g/L,with 15%(w/w)of GLA in cellular lipids.
基金supported by the National Natural Science Foundation of China(Nos.82173479 and 81872579)Jiangsu Provincial Maternal and Child Health Scientific Research Project(No.F201907).
文摘4-Nitrophenol(4-NP),as a toxic and refractory pollutant,has generated significant concern due to its adverse effects.However,the potential toxic effects andmechanism remained unclear.In this study,the reproduction,development,locomotion and reactive oxygen species(ROS)production of Caenorhabditis elegans were investigated to evaluate the 4-NP toxicity.We used metabolomics to assess the potential damage mechanisms.The role of metabolites in mediating the relationship between 4-NP and phenotypes was examined by correlation and mediation analysis.4-NP(8 ng/L and 8μg/L)caused significant reduction of brood size,ovulation rate,total germ cells numbers,head thrashes and body bends,and an increase in ROS.However,the oosperm numbers in uterus,body length and body width were decreased in 8μg/L.Moreover,36 differential metabolites were enriched in the significant metabolic pathways,including lysine biosynthesis,β-alanine metabolism,tryptophan metabolism,pentose phosphate pathway,pentose and glucuronate interconversions,amino sugar and nucleotide sugar metabolism,starch and sucrose metabolism,galactose metabolism,propanoate metabolism,glycerolipid metabolism,and estrogen signaling pathway.The mechanism of 4-NP toxicity was that oxidative stress caused by the perturbation of amino acid,which had effects on energy metabolism through disturbing carbohydrate and lipid metabolism,and finally affected the estrogen signaling pathway to exert toxic effects.Moreover,correlation and mediation analysis showed glycerol-3P,glucosamine-6P,glucosamine-1P,UDP-galactose,L-aspartic acid,and uracilwere potential markers for the reproduction and glucose-1,6P2 for developmental toxicity.The results provided insight into the pathways involved in the toxic effects caused by 4-NP and developed potential biomarkers to evaluate 4-NP toxicity.
基金supported by the National Natural Science Foundation of China (No. 30870810)National Basic Research Program of China (No. 2011CB933404)
文摘Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibitory sensory stimuli was modulated by changing the metal ion barrier.Moreover,the hen-1,ttx-3 and casy-1 mutants having known defects in integrative response were used to evaluate the modulated assay systems.Based on the examined assay systems,new genes possibly involved in the sensory integration control were identified.Results In the presence of different metal ion barriers and diacetyl,locomotion behaviors,basic movements,pan-neuronal,cholinergic and GABAergic neuronal GFP expressions,neuronal development,structures of sensory neurons and interneurons,and stress response of nematodes in different regions of examined assay systems were normal,and chemotaxis toward different concentrations of diacetyl and avoidance of different concentrations of metal ions were inhibited.In the first group,most of the nematodes moved to diacetyl by crossing the barrier of Fe2＋,Zn2＋,or Mn2＋.In the second group,almost half of the nematodes moved to diacetyl by crossing the barrier of Ag＋,Cu2＋,Cr2＋,or Cd2＋.In the third group,only a small number of nematodes moved to diacetyl by crossing the barrier of Pb2＋ or Hg2＋.Moreover,when nematodes encountered different metal ion barriers during migration toward diacetyl,the percentage of nematodes moving back and then turning and that of nematodes moving straight to diacetyl were very different.With the aid of examined assay systems,it was found that mutations of fsn-1 that encodes a F-box protein,and its target scd-2 that encodes a receptor tyrosine kinase,caused severe defects in integrative response,and the sensory integration defects of fsn-1 mutants were obviously inhibited by scd-2 mutation.Conclusion Based on the nematode behaviors in examined assay systems,3 groups of assay systems were obtained.The first group may be helpful in evaluating or identifying the very subtle deficits in sensory integration,and the third group may be useful for the final confirmation of sensory integration defects of mutants identified in the first or the second group of assay systems.Furthermore,the important association of sensory integration regulation with stabilization or destabilization of synaptic differentiation may exist in C.elegans.
文摘Objective To examine the important roles of microRNAs （miRNAs） in regulating amphid structure and function, we performed a computational analysis for the genetic loci required for the sensory perception and their possibly corresponding miRNAs in C. elegans. Methods Total 55 genetic loci required for the amphid structure and function were selected. Sequence alignment was combined with E value evaluation to investigate and identify the possible corresponding miRNAs. Results Total 30 genes among the 55 genetic loci selected have their possible corresponding regulatory miRNA（s）, and identified genes participate in the regulation of almost all aspects of amphid structure and function. In addition, our data suggest that both the amphid structure and the amphid functions might be regulated by a series of network signaling pathways. Moreover, the distribution of miRNAs along the 3＇ untranslated region （UTR） of these 30 genes exhibits different patterns. Conclusion We present the possible miRNA-mediated signaling pathways involved in the regulation of chemosensation and thermosensation by controlling the corresponding sensory neuron and interneuron functions. Our work will be useful for better understanding of the miRNA-mediated control of the chemotaxis and thermotaxis in C. elegans.
基金supported by the grants from the National Natural Science Foundation of China(No. 30771113, 30870810)the Program for New Century Excellent Talents in University
文摘Objective To investigate whether genes required for synaptogenesis and synaptic function are also involved in fat storage control in Caenorhabditis elegans. Methods Fat storage was examined in mutants of genes affecting the synaptogenesis and synaptic function. In addition, the genetic interactions of SNAREs syntaxin/unc-64 and SNAP-25/ric-4 with daf-2, daf-7, nhr-49, sbp-1 and mdt-15 in regulating fat storage were further investigated. The tissue-specific activities of unc-64 and ric-4 were investigated to study the roles of unc-64 and ric-4 in regulating fat storage in the nervous system and/or the intestine. Results Mutations of genes required for the formation of presynaptic neurotransmission site did not obviously influence fat storage. However, among the genes required for synaptic function, the plasma membrane-associated SNAREs syntaxin/unc-64 and SNAP-25/ric-4 genes were involved in the fat storage control. Fat storage in the intestinal cells was dramatically increased in unc-64 and ric-4 mutants as revealed by Sudan Black and Nile Red strainings, although the fat droplet size was not significantly changed. Moreover, in both the nervous system and the intestine, expression of unc-64 significantly inhibited the increase in fat storage observed in unc-64 mutant. And expression of ric-4 in the nervous system completely restored fat storage in ric-4 mutant. Genetic interaction assay further indicated that both unc-64 and ric-4 regulated fat storage independently of daf-2 [encoding an insulin-like growth factor-I （IGF-I） receptor], daf-7 [encoding a transforming growth factor-β （TGF-β） ligand], and nhr-49 （encoding a nuclear hormone receptor）. Besides, mutation of daf-16 did not obviously affect the phenotype of increased fat storage in unc-64 or ric-4 mutant. Furthermore, unc-64 and ric-4 regulated fat storage probably through the ARC105/mdt-15- and SREBP/sbp-1-mediated signaling pathways. In addition, fat storage in unc-64; ric-4 was higher than that in either unc-64 or ric-4 single mutant nematodes, suggesting that unc-64 functions in parallel with ric-4 in regulating fat storage. Conclusion The plasma membrane-associated SNAREs syntaxin/ unc-64 and SNAP-25/ric-4 function in parallel in regulating fat storage in C. elegans, probably through the ARC105/mdt-15- and SREBP/sbp-1-mediated signaling pathways.
基金supported by the National Natural Science Foundation of China (No. 30771113,30870810)the Program for New Century Excellent Talents in University
文摘Objective To investigate the interaction between the genes required for the functions of AWA olfactory neuron and insulin/IGF signaling in regulating the longevity of nematode Caenorhabditis elegans （C. elegans）. Methods The mutants that had loss-of-function mutation of the genes required for AWA, AWC, ASE, and AFD sensory neurons were employed. Lifespan, the speed of pharynx pumping, the intestinal autofluorescence, the dauer formation, and the brood size were examined. Rescue experiments were performed to confrm the role of the genes required for the functions of AWA neuron in regulating lifespan. Moreover, genetic interactions between genes required for the functions of AWA neuron and insulin/ IGF signaling were investigated. Results Mutations of odr-7, odr-2, and odr-3 genes required for the functions of AWA neuron significantly increased the mean lifespan of nematodes and slowed the accumulation of intestinal autofluorescence. Besides, these mutations were closely associated with higher pumping rates during aging. However, mutation of odr-7, odr- 2, or odr-3 did not obviously affect the brood size or the dauer formation, and the regulation of longevity by odr-7, odr-2, and odr-3 was temperature-independent. In contrast, mutations of genes required for the functions of ASE, AWC, and AFD sensory neurons did not infuence the nematode lifespan. Moreover, expression of odr-7, odr-2 and odr-3 in AWA neuron could completely or largely restore the altered lifespan in odr-7, odr-2 and odr-3 mutants. Furthermore, genetic interaction assay demonstrated that the extended lifespan in odr-7 mutant could be suppressed by daf-16 mutation and enhanced by daf- 2 or age-1 mutation, whereas mev-1 and pha-4 were not required for the long lifespan of odr-7 mutant. Conclusion The genes required for the function of AWA sensory neuron could regulate the nematode longevity in an insulin/IGF signaling-dependent fashion in C. elegans.
文摘Objective To identify new genes required for neurosecretory control of aging in C. elegans. Methods In view of the importance of nervous system in aging regulation, we performed the screen for genes involved in the aging regulation from genetic loci encoding synaptic proteins by lifespan assay and accumulation of lipofuscin autofluorescence. We further investigated the dauer formation phenotypes of their corresponding mutants and whether they were possibly up-regulated by the insulin-like signaling pathway. Results The genetic loci of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd- 2, snb-1, ric-4, nrx-1, unc-13, sbt-1 and unc-64 might be involved in the aging control. In addition, functions of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd-2, snb-1, ric-4 and nrx-1 in regulating aging may be opposite to those of unc-13, sbt-1 and unc-64. The intestinal autofluorescence assay further indicated that the identified long-lived and short-lived mutants were actually due to the suppressed or accelerated aging. Among the identified genes, syd-2, hlb-1, mkk-4, scd-2, snb-1, ric-4 and unc-64 were also involved in the control of dauer formation. Moreover, daf-2 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, ric-4, sbt-1, rpm-1, unc-10, dlk- 1 and unc-13. The daf-16 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, sbt-1, rpm-1, unc-10, dlk-1 and unc-13. Conclusion These data suggest the possibly important status of the synaptic transmission to the animal＇ s life-span control machinery, as well as the dauer formation control.
基金the National Natural Science Foundation of China (No. 30771113, 30870810)the Program for New Century Excellent Talents in University, Ministry of Education, China
文摘Objective To study the role of HLB-1 in regulating the organization and function of neuromuscular junctions in nematode Caenorhabditis elegans. Methods To evaluate the functions of HLB-1 in regulating the organization and function of neuromuscular junctions, effects of hlb-1 mutation on the synaptic structures were revealed by uncovering the expression patterns of SNB-1 ：：GFP and UNC-49：GFP, and pharmacologic assays with aldicarb and levamisole were also used to test the synaptic functions. Further rescue and mosaic analysis confirmed HLB-1＇s role in regulating the organization and function of neuromuscular junctions. Results Loss of HLB-1 function did not result in defects in neuronal outgrowth or neuronal loss, but caused obvious defects of SNB-1：：GFP and UNC-49：：GFP puncta localization, suggesting the altered presynaptic and postsynaptic structures. The mutant animals exhibited severe defects in locomotion behaviors and altered responses to an inhibitor of acetylcholinesterase and a cholinergic agonist, indicating the altered presynaptic and postsynaptic functions. Rescue and mosaic analysis experiments suggested that HLB-1 regulated synaptic functions in a cell nonautonomously way. Moreover, HLB- 1 expression was not required for the presynaptic active zone morphology. Genetic evidence further demonstrated that hlb-1 acted in a parallel pathway with syd-2 to regulate the synaptic functions. Conclusion HLB-1 appeared as a new regulator for the organization and function of neuromuscular junctions in C. elegans.
文摘Objective To screen and identify genetic loci affecting the active zone formation in C. elegans. Methods A SYD-2：：GFP reporter was constructed and used as an active zone marker for forward genetic screen to identify genetic loci affecting the active zone formation. Results Eight isolated mutant alleles were characterized from 15,000 haploid genomes. The SYD-2：：GFP phenotypes of these mutants are mainly reflected as the changes of number, morphology, distribution of puncta and the gaps appearance. Some mutants also exhibit visible behavioral or physical phenotypes, and aldicarb resistant or sensitive phenotypes. Conclusion These mutants provide the opportunity for further systematic research on the active zone formation and the neurotransmission.
基金supported by grants from the National Natural Science Foundation of China (No.30771113, 30870810)the Program for New Century Excellent Talents in Universitythe Innovative Research Program for Undergraduates in China (No. C2007052)
文摘Objective To investigate the role of environmental factor—temperature in the regulation of aging process by unc-13 and sbt-1 in Caenorhabditis elegans. Methods The lifespan, the speed of pharynx pumping, and the intestinal autofluorescence of unc-13 and sbt-1 mutants were examined at different temperature conditions. In addition, to exclude the possible influences from other factors in unc-13 and sbt-1 mutants, the dauer formation, the thermotaxis, the brood size and the population percentage of the mutants expressing hsp16.2-gfp were further investigated. Results Mutations of unc-13 and sbt-1 significantly increased the mean and the maximum lifespans of nematodes cultured at 20 oC and 25 oC, while no noticeable increase was found at 15 oC in either the mean or the maximum lifespan. Investigations on the speed of pharynx pumping and the intestinal autofluorescence suggested that at 20 oC and 25 oC, mutations of unc-13 and sbt-1 could slow the aging process and delay the accumulation of aging-related cellular damage. Meanwhile, mutations of unc-13 or sbt-1 did not affect the dauer formation or the thermotaxis to different temperatures in nematodes. In contrast, at 20 oC and 25 oC conditions, mutations of unc-13 and sbt-1 significantly decreased the brood size and the percentage of nematodes expressing hsp16.2-gfp, while no such differences were detected at 15 oC. Moreover, the thermotolerance of unc-13 and sbt-1 mutants could be greatly strengthened after the 16-h heat shock at 35 oC. Conclusion The regulation of aging by unc-13 and sbt-1 is temperature-dependent. And the alterations in reproduction capability and stress response may be associated with the formation of this temperature-dependent property.
文摘Objective To investigate the toxic effect of environmental neurotoxin MPP^＋ to C.elegans and identify the mechanisms that cause the toxicity.Methods Humanα-synuclein transgenic C.elegans was used as the animal model,the toxic effect of MPP^＋ to dopamine（DA）neurons and the lifespan of worms was tested.The worms were feed with OP50 to determine whether ATP increase can rescue the worm from toxicity.ATP level and aberrant protein accumulation were analyzed in the MPP^＋ treated worms with or without OP50 addition.Results We found that MPP^＋ induced DA cell death and worm lethality,which could be prevented by OP50 treatment.OP50 exerted the protective effect by up-regulating ATP level,even though it also induced accumulation ofα-synuclein.Despite the undefined role of protein aggregation to the cell death,our results showed that the toxicity of MPP^＋ was mainly caused by the ATP depletion in theα-synuclein transgenic C.elegans.Conclusion MPP^＋ could induce DA neuronal death and worm lethality inα-synuclein transgenic C.elegans;Compared with the aggregation ofα-synuclein,the major cause of MPP^＋ toxicity appeared due to ATP depletion.
