Enhanced branched-chain amino acid metabolism improves age-related reproduction in C. elegans.

Reproductive ageing is one of the earliest human ageing phenotypes, and mitochondrial dysfunction has been linked to oocyte quality decline; however, it is not known which mitochondrial metabolic processes are critical for oocyte quality maintenance with age. To understand how mitochondrial processes contribute to Caenorhabditis elegans oocyte quality, we characterized the mitochondrial proteomes of young and aged wild-type and long-reproductive daf-2 mutants. Here we show that the mitochondrial proteomic profiles of young wild-type and daf-2 worms are similar and share upregulation of branched-chain amino acid (BCAA) metabolism pathway enzymes. Reduction of the BCAA catabolism enzyme BCAT-1 shortens reproduction, elevates mitochondrial reactive oxygen species levels, and shifts mitochondrial localization. Moreover, bcat-1 knockdown decreases oocyte quality in daf-2 worms and reduces reproductive capability, indicating the role of this pathway in the maintenance of oocyte quality with age. Notably, oocyte quality deterioration can be delayed, and reproduction can be extended in wild-type animals both by bcat-1 overexpression and by supplementing with vitamin B1, a cofactor needed for BCAA metabolism.

Schisandrin A enhances pathogens resistance by targeting a conserved p38 MAPK pathway.

Schizandrin A (SA), also known as deoxyschizandrin, is one of the most biologically active lignans isolated from the traditional Chinese medicine Fructus schisandrae chinensis. Schisandrin A has proven benefits for anti-cancer, anti-inflammation, hepatoprotection, anti-oxidation, neuroprotection, anti-diabetes. But the influence of Schisandrin A to the innate immune response and its molecular mechanisms remain obscure. In this study, we found that Schisandrin A increased resistance to not only the Gram-negative pathogens Pseudomonas aeruginosa and Salmonella enterica but also the Gram-positive pathogen Listeria monocytogenes. Meanwhile, Schisandrin A protected the animals from the infection by enhancing the tolerance to the pathogens infection rather than by reducing the bacterial burden. Through the screening of the conserved immune pathways in Caenorhabditis elegans, we found that Schisandrin A enhanced innate immunity via p38 MAPK pathway. Furthermore, Schisandrin A increased the expression of antibacterial peptide genes, such as K08D8.5, lys-2, F35E12.5, T24B8.5, and C32H11.12 by activation PMK-1/p38 MAPK. Importantly, Schisandrin A-treated mice also enhanced resistance to P. aeruginosa PA14 infection and significantly increased the levels of active PMK-1. Thus, promoted PMK-1/p38 MAPK-mediated innate immunity by Schisandrin A is conserved from worms to mammals. Our work provides a conserved mechanism by which Schisandrin A enhances innate immune response and boosts its therapeutic application in the treatment of infectious diseases.

A bacterial pathogen induces developmental slowing by high reactive oxygen species and mitochondrial dysfunction in Caenorhabditis elegans.

Host-pathogen interactions are complex by nature, and the host developmental stage increases this complexity. By utilizing Caenorhabditis elegans larvae as the host and the bacterium Pseudomonas aeruginosa as the pathogen, we investigated how a developing organism copes with pathogenic stress. By screening 36 P. aeruginosa isolates, we found that the CF18 strain causes a severe but reversible developmental delay via induction of reactive oxygen species (ROS) and mitochondrial dysfunction. While the larvae upregulate mitophagy, antimicrobial, and detoxification genes, mitochondrial unfolded protein response (UPRmt) genes are repressed. Either antioxidant or iron supplementation rescues the phenotypes. We examined the virulence factors of CF18 via transposon mutagenesis and RNA sequencing (RNA-seq). We found that non-phenazine toxins that are regulated by quorum sensing (QS) and the GacA/S system are responsible for developmental slowing. This study highlights the importance of ROS levels and mitochondrial health as determinants of developmental rate and how pathogens can attack these important features.

EAT-2 attenuates C. elegans development via metabolic remodeling in a chemically defined food environment.

Dietary intake and nutrient composition regulate animal growth and development; however, the underlying mechanisms remain elusive. Our previous study has shown that either the mammalian deafness homolog gene tmc-1 or its downstream acetylcholine receptor gene eat-2 attenuates Caenorhabditis elegans development in a chemically defined food CeMM (C. elegans maintenance medium) environment, but the underpinning mechanisms are not well-understood. Here, we found that, in CeMM food environment, for both eat-2 and tmc-1 fast-growing mutants, several fatty acid synthesis and elongation genes were highly expressed, while many fatty acid ß-oxidation genes were repressed. Accordingly, dietary supplementation of individual fatty acids, such as monomethyl branch chain fatty acid C17ISO, palmitic acid and stearic acid significantly promoted wild-type animal development on CeMM, and mutations in either C17ISO synthesis gene elo-5 or elo-6 slowed the rapid growth of eat-2 mutant. Tissue-specific rescue experiments showed that elo-6 promoted animal development mainly in the intestine. Furthermore, transcriptome and metabolome analyses revealed that elo-6/C17ISO regulation of C. elegans development may be correlated with up-regulating expression of cuticle synthetic and hedgehog signaling genes, as well as promoting biosynthesis of amino acids, amino acid derivatives and vitamins. Correspondingly, we found that amino acid derivative S-adenosylmethionine and its upstream metabolite methionine sulfoxide significantly promoted C. elegans development on CeMM. This study demonstrated that C17ISO, palmitic acid, stearic acid, S-adenosylmethionine and methionine sulfoxide inhibited or bypassed the TMC-1 and EAT-2-mediated attenuation of development via metabolic remodeling, and allowed the animals to adapt to the new nutritional niche.

Ameliorative effect of Luffa cylindrica fruits on Caenorhabditis elegans and cellular models of Alzheimer's disease-related pathology via autophagy induction.

BACKGROUND: Alzheimer's disease (AD) is a prevalent neurodegenerative disorder without an effective cure. Natural products, while showing promise as potential therapeutics for AD, remain underexplored. AIMS: This study was conducted with the goal of identifying potential anti-AD candidates from natural sources using Caenorhabditis elegans (C. elegans) AD-like models and exploring their mechanisms of action. MATERIALS & METHODS: Our laboratory's in-house herbal extract library was utilized to screen for potential anti-AD candidates using the C. elegans AD-like model CL4176. The neuroprotective effects of the candidates were evaluated in multiple C. elegans AD-like models, specifically targeting Aß- and Tau-induced pathology. In vitro validation was conducted using PC-12 cells. To investigate the role of autophagy in mediating the anti-AD effects of the candidates, RNAi bacteria and autophagy inhibitors were employed. RESULTS: The ethanol extract of air-dried fruits of Luffa cylindrica (LCE), a medicine-food homology species, was found to inhibit Aß- and Tau-induced pathology (paralysis, ROS production, neurotoxicity, and Aß and pTau deposition) in C. elegans AD-like models. LCE was non-toxic and enhanced C. elegans' health. It was shown that LCE activates autophagy and its anti-AD efficacy is weakened with the RNAi knockdown of autophagy-related genes. Additionally, LCE induced mTOR-mediated autophagy, reduced the expression of AD-associated proteins, and decreased cell death in PC-12 cells, which was reversed by autophagy inhibitors (bafilomycin A1 and 3-methyladenine). DISCUSSION: LCE, identified from our natural product library, emerged as a valuable autophagy enhancer that effectively protects against neurodegeneration in multiple AD-like models. RNAi knockdown of autophagy-related genes and cotreatment with autophagy inhibitors weakened its anti-AD efficacy, implying a critical role of autophagy in mediating the neuroprotective effects of LCE. CONCLUSION: Our findings highlight the potential of LCE as a functional food or drug for targeting AD pathology and promoting human health.

Shenqi formula delayed Alzheimer's disease-like symptoms by skn-1 pathway in Caernorhabditis elegans.

ETHNOPHARMACOLOGICAL RELEVANCE: Shenqi formula is composed of Codonopsis pilosula (Cp) and Lycium barbarum (Lb), and it is traditionally used for promoting qi and nourishing the spleen, liver and kidney. Cp and Lb have been reported to improve cognitive performance in APP/PS1 mice, prevent the accumulation of Aß, and reduce the neurotoxicity of Aß to achieve the anti-Alzheimer's disease (AD) effect. AIM OF THE STUDY: Shenqi formula was explored the therapeutic effect on Caenorhabditis elegans AD pathological model and the underlying mechanism of action. MATERIALS AND METHODS: Paralysis assay and serotonin sensitivity assay was used to detect whether Shenqi formula can alleviate AD paralysis phenotype, and then DPPH, ABTS, NBT and Fenton methods were applied to investigate the scavenging capacity to free radical, ROS, ·O2- and ·OH of Shenqi formula in vitro. H2DCF-DA and MitoSOX™ Red were employed to measure ROS and .O2- accumulation, respectively. RNAi was used to knock down the expression of skn-1 and daf-16 related to oxidative stress resistance signalling pathway. Fluorescence microscopy was used to record the expression of SOD-3::GFP, GST-4::GFP, SOD-1::YFP, and the nuclear translocation of SKN-1 and DAF-16. Western blot assay was carried out to test Aß monomers and oligomers. RESULTS: Shenqi formula delayed the AD-like pathological characteristics in C. elegans, and the complete Shenqi formula was more effective than Cp or Lb alone. The effect of Shenqi formula on delaying worm paralysis was partially eliminated by skn-1 RNAi, but not daf-16 RNAi. Shenqi formula significantly inhibited the abnormal deposition of Aß protein, decreased Aß protein monomers and oligomers. It increased the expressions of gst-4, sod-1, and sod-3 similar to paraquat, companied by rise then fall of ROS and .O2- in AD worms. CONCLUSIONS: Shenqi formula at least partially depended on SKN-1 signalling pathway to exert its anti-AD effect, and it is potential to be used as a kind of health food to prevent the progress of AD.

Targeting autophagy to discover the Piper wallichii petroleum ether fraction exhibiting antiaging and anti-Alzheimer's disease effects in Caenorhabditis elegans.

BACKGROUND: With population aging, the incidence of aging-related Alzheimer's disease (AD) is increasing, accompanied by decreased autophagy activity. At present, Caenorhabditis elegans (C. elegans) is widely employed to evaluate autophagy and in research on aging and aging-related diseases in vivo. To discover autophagy activators from natural medicines and investigate their therapeutic potential in antiaging and anti-AD effects, multiple C. elegans models related to autophagy, aging, and AD were used. METHOD: In this study, we employed the DA2123 and BC12921 strains to discover potential autophagy inducers using a self-established natural medicine library. The antiaging effect was evaluated by determining the lifespan, motor ability, pumping rate, lipofuscin accumulation of worms, and resistance ability of worms under various stresses. In addition, the anti-AD effect was examined by detecting the paralysis rate, food-sensing behavior, and amyloid-ß and Tau pathology in C. elegans. Moreover, RNAi technology was used to knock down the genes related to autophagy induction. RESULTS: We discovered that Piper wallichii extract (PE) and the petroleum ether fraction (PPF) activated autophagy in C. elegans, as evidenced by increased GFP-tagged LGG-1 foci and decreased GFP-p62 expression. In addition, PPF extended the lifespan and enhanced the healthspan of worms by increasing body bends and pumping rates, decreasing lipofuscin accumulation, and increasing resistance to oxidative, heat, and pathogenic stress. Moreover, PPF exhibited an anti-AD effect by decreasing the paralysis rate, improving the pumping rate and slowing rate, and alleviating Aß and Tau pathology in AD worms. However, the feeding of RNAi bacteria targeting unc-51, bec-1, lgg-1, and vps-34 abolished the antiaging and anti-AD effects of PPF. CONCLUSION: Piper wallichii may be a promising drug for antiaging and anti-AD. More future studies are also needed to identify autophagy inducers in Piper wallichii and clarify their molecular mechanisms.

Protein-rich yeast extract (®fermgard) has potential antioxidant and anti-aging activities.

There existed a deficiency in the research on the nutritional activities of microbial (yeast) active substances in antioxidant and anti-aging activities, although the research objects were concentrated in animals and plants in recent years. In this study, the anti-oxidant and anti-aging activities of protein-rich yeast extract (®fermgard) (YE) were investigated through Caenorhabditis elegans (C. elegans). The results indicated that YE could improve the lifespan and anti-stress ability by up-regulating the activities of antioxidant enzymes in C. elegans. Meanwhile, the mRNA transcriptional level of daf-16, skn-1 and sod-3 was significantly up-regulated. In addition, the composition and level of the gut microbiota and metabolite were modulated. YE exerts antioxidant and anti-aging activities by regulating the expression of anti-oxidation-related mRNA, gut microbiota and metabolites in C. elegans, providing a basis for exploring the deep mechanism of YE improving health. At the same time, it provides new ideas for the development of functional foods.

Lysosomal chloride transporter CLH-6 protects lysosome membrane integrity via cathepsin activation.

Lysosomal integrity is vital for cell homeostasis, but the underlying mechanisms are poorly understood. Here, we identify CLH-6, the C. elegans ortholog of the lysosomal Cl-/H+ antiporter ClC-7, as an important factor for protecting lysosomal integrity. Loss of CLH-6 affects lysosomal degradation, causing cargo accumulation and membrane rupture. Reducing cargo delivery or increasing CPL-1/cathepsin L or CPR-2/cathepsin B expression suppresses these lysosomal defects. Inactivation of CPL-1 or CPR-2, like CLH-6 inactivation, affects cargo digestion and causes lysosomal membrane rupture. Thus, loss of CLH-6 impairs cargo degradation, leading to membrane damage of lysosomes. In clh-6(lf) mutants, lysosomes are acidified as in wild type but contain lower chloride levels, and cathepsin B and L activities are significantly reduced. Cl- binds to CPL-1 and CPR-2 in vitro, and Cl- supplementation increases lysosomal cathepsin B and L activities. Altogether, these findings suggest that CLH-6 maintains the luminal chloride levels required for cathepsin activity, thus facilitating substrate digestion to protect lysosomal membrane integrity.

D-chiro-inositol increases antioxidant capacity and longevity of Caenorhabditis elegans via activating Nrf-2/SKN-1 and FOXO/DAF-16.

D-chiro-inositol (DCI) is an isomer of inositol, abundant in many foods, such as beans and buckwheat, with insulin-sensitizing, anti-inflammatory, and antioxidant effects. DCI has been used to relieve insulin resistance in diabetes and polycystic ovary syndrome in combination with inositol or D-pinitol. Here, we investigated the effect of DCI on aging and stress resistance in C. elegans. We found that DCI could prolong the lifespan of C. elegans by up to 29.6 %. DCI significantly delayed the onset of neurodegenerative diseases in models of C. elegans. DCI decreased the accumulation of Aß1-42, alpha-synuclein, and poly-glutamine, the pathological causes of Alzheimer's, Parkinson's, and Huntington's diseases, respectively. DCI significantly increased the stress resistances against pathogens, oxidants and heat shock. Moreover, D-chiro-inositol reduced the content of ROS and malondialdehyde by increasing the total antioxidant capacity and the activity of superoxide dismutase and catalase. Above effects of DCI requires the transcription factors FOXO/DAF-16 and Nrf-2/SKN-1. DCI also increased the expression of downstream genes regulated by FOXO/DAF-16 and Nrf-2/SKN-1. In conclusion, DCI enhanced the antioxidant capacity and healthy lifespan of C. elegans by activating DAF-16, SKN-1, and HSF-1. Our results showed that DCI could be a promising antiaging agent that is worth further research on the mechanism and health supplemental application of DCI.

Effect of omega-6 linoleic acid on neurobehavioral development in Caenorhabditis elegans.

Linoleic acid (LA, omega-6), an essential polyunsaturated fatty acid, is supplied by vegetable oils such as corn, sunflower and soybean. Supplementary LA in infants and children is required for normal growth and brain development, but has also been reported to induce brain inflammation and neurodegenerative diseases. This controversial role of LA development requires further investigation. Our study utilized Caenorhabditis elegans (C. elegans) as a model to clarify the role of LA in regulating neurobehavioral development. A mere supplementary quantity of LA in C. elegans larval stage affected the worm's locomotive ability, intracellular ROS accumulation and lifespan. We found that more serotonergic neurons were activated by supplementing LA above 10 µM thereby promoting locomotive ability with upregulation of serotonin-related genes. Supplementation with LA above 10 µM also inhibited the expression of mtl-1, mtl-2 and ctl-3 to accelerate oxidative stress and attenuate lifespan in nematodes; however, enhancement of stress-related genes such as sod-1, sod-3, mtl-1, mtl-2 and cyp-35A2 by supplementary LA under 1 µM decreased oxidative stress and increased the worm's lifespan. In conclusion, our study reveals that supplementary LA possesses both pros and cons in worm physiology and provides new suggestions for LA intake administration in childhood.

Anti-Oxidative and Anti-Aging Effects of Probiotic Fermented Ginseng by Modulating Gut Microbiota and Metabolites in Caenorhabditis elegans.

Antioxidative and antiaging abilities of probiotic fermented ginseng (PG) were evaluated in Caenorhabditis elegans (C. elegans). Lifespan and effect on heat stress and acute oxidative stress in C. elegans were significantly enhanced by PG. Antioxidative enzymes such as T-SOD, GSH-PX, CAT were significantly up-regulated, and MDA, ROS and apoptosis levels were significantly down-regulated. At the same time, PG exerted antioxidant and anti-aging activities by reducing the expression of DAF-2 mRNA and increasing the expression of SKN-1 and SOD-3 mRNA in C. elegans. In addition, the mechanism of antioxidative and antiaging activities of PG was explored through gut microbiota sequencing and untargeted metabolomics. The results of gut microbiota indicated that PG could significantly improve the composition and structure of microbes in the gut of C. elegans, and the relative abundance of beneficial bacteria was up-regulated. Untargeted metabolomic results elucidated that PG modulated antioxidant and antiaging activities through neuroactive ligand-receptor interaction, Citrate cycle (TCA cycle), pyruvate metabolism, ascorbate and aldarate metabolism and D-Arginine and D-ornithine metabolism of C. elegans. These results indicated that PG had excellent antioxidant and anti-aging activities, providing research value for the development of functional foods and improvement of aging-related diseases.

Coupling of autophagy and the mitochondrial intrinsic apoptosis pathway modulates proteostasis and ageing in Caenorhabditis elegans.

Mitochondria preserve metabolic homeostasis and integrate stress signals, to trigger cytoprotective, or cell death pathways. Mitochondrial homeostasis and function decline with age. The mechanisms underlying the deterioration of mitochondrial homeostasis during ageing, or in age-associated pathologies, remain unclear. Here, we show that CISD-1, a mitochondrial iron-sulfur cluster binding protein, implicated in the pathogenesis of Wolfram neurodegenerative syndrome type 2, modulates longevity in the nematode Caenorhabditis elegans by engaging autophagy and the mitochondrial intrinsic apoptosis pathway. The anti-apoptotic protein CED-9 is the downstream effector that mediates CISD-1-dependent effects on proteostasis, neuronal integrity and lifespan. Moreover, intracellular iron abundance is critical for CISD-1 function, since mild iron supplementation is sufficient to decelerate ageing and partly ameliorate the disturbed mitochondrial bioenergetics and proteostasis of CISD-1 deficient animals. Our findings reveal that CISD-1 serves as a mechanistic link between autophagy and the apoptotic pathway in mitochondria to differentially modulate organismal proteostasis and ageing, and suggest novel approaches which could facilitate the treatment of Wolfram Syndrome or related diseases.

Linolenic acid ameliorates sarcopenia in C. elegans by promoting mitophagy and fighting oxidative stress.

Sarcopenia is a syndrome of age-related loss of muscle mass and strength that seriously affects human health, and there are currently no effective drugs to treat the disease. Linolenic acid as a common n-3 polyunsaturated fatty acid (n-3 PUFA) is known to have many beneficial functions. Some studies have found that n-3 PUFA might have the potential to improve sarcopenia. In this study, Caenorhabditis elegans (C. elegans) was used as a model animal to investigate the effects of linolenic acid on C. elegans muscles. The results showed that 50 µg mL-1 linolenic acid significantly improved sarcopenia by repairing mitochondrial function by promoting mitophagy and fighting oxidative stress (p < 0.05). This included the increase of the expression of the mitophagy gene pink-1 and DAF-16/FOXO transcription factors, respectively, by linolenic acid. This study could provide some evidence for the application of n-3 PUFA in improving sarcopenia.

Early-life starvation alters lipid metabolism in adults to cause developmental pathology in Caenorhabditis elegans.

Early-life malnutrition increases adult disease risk in humans, but the causal changes in gene regulation, signaling, and metabolism are unclear. In the roundworm Caenorhabditis elegans, early-life starvation causes well-fed larvae to develop germline tumors and other gonad abnormalities as adults. Furthermore, reduced insulin/IGF signaling during larval development suppresses these starvation-induced abnormalities. How early-life starvation and insulin/IGF signaling affect adult pathology is unknown. We show that early-life starvation has pervasive effects on adult gene expression which are largely reversed by reduced insulin/IGF signaling following recovery from starvation. Early-life starvation increases adult fatty-acid synthetase fasn-1 expression in daf-2 insulin/IGF signaling receptor-dependent fashion, and fasn-1/FASN promotes starvation-induced abnormalities. Lipidomic analysis reveals increased levels of phosphatidylcholine in adults subjected to early-life starvation, and supplementation with unsaturated phosphatidylcholine during development suppresses starvation-induced abnormalities. Genetic analysis of fatty-acid desaturases reveals positive and negative effects of desaturation on development of starvation-induced abnormalities. In particular, the ω3 fatty-acid desaturase fat-1 and the Δ5 fatty-acid desaturase fat-4 inhibit and promote development of abnormalities, respectively. fat-4 is epistatic to fat-1, suggesting that arachidonic acid-containing lipids promote development of starvation-induced abnormalities, and supplementation with ARA enhanced development of abnormalities. This work shows that early-life starvation and insulin/IGF signaling converge on regulation of adult lipid metabolism, affecting stem-cell proliferation and tumor formation.

Black rice anthocyanin extract enhances the antioxidant capacity in PC12 cells and improves the lifespan by activating IIS pathway in Caenorhabditis elegans.

Black rice is rich in anthocyanins, and the antioxidant effect of anthocyanins is recognized by consumers. The aim of this study was to identify the molecular mechanisms underlying the antioxidant activity of black rice anthocyanin extract (BRAE) in PC12 cells and C. elegans. Results showed that BRAE increased antioxidant enzyme activities and decreased the accumulation of reactive oxygen species (ROS) and malondialdehyde in PC12 cells induced by H2O2. Meanwhile, BRAE extended the lifespan, enhanced resistance to stress, increased antioxidant enzyme activities, and reduced lipofuscin, ROS, and MDA accumulation in wild-type C. elegans. The polyQ40 aggregation in AM141, paralysis in CL4176, and chemotaxis deficit in CL2355 were alleviated by BRAE administration. BRAE downregulated the mRNA expression of age-1 and daf-2, while upregulated the daf-16 mRNA level and SOD-3, CTL-1, and GST-4 protein expression. Mutational lifespan tests and molecular docking showed that insulin pathway might be involved in the mechanism of lifespan extension.

Orsay Virus Infection of Caenorhabditis elegans Is Modulated by Zinc and Dependent on Lipids.

Viruses utilize host lipids to promote the viral life cycle, but much remains unknown as to how this is regulated. Zinc is a critical element for life, and few studies have linked zinc to lipid homeostasis. We demonstrated that Caenorhabditis elegans infection by Orsay virus is dependent upon lipids and that mutation of the master regulator of lipid biosynthesis, sbp-1, reduced Orsay virus RNA levels by ~236-fold. Virus infection could be rescued by dietary supplementation with lipids downstream of fat-6/fat-7. Mutation of a zinc transporter encoded by sur-7, which suppresses the lipid defect of sbp-1, also rescued Orsay virus infection. Furthermore, reducing zinc levels by chemical chelation in the sbp-1 mutant also increased lipids and rescued Orsay virus RNA levels. Finally, increasing zinc levels by dietary supplementation led to an ~1,620-fold reduction in viral RNA. These findings provide insights into the critical interactions between zinc and host lipids necessary for virus infection. IMPORTANCE Orsay virus is the only known natural virus pathogen of Caenorhabditis elegans, which shares many evolutionarily conserved pathways with humans. We leveraged the powerful genetic tractability of C. elegans to characterize a novel interaction between zinc, lipids, and virus infection. Inhibition of the Orsay virus replication in the sbp-1 mutant animals, explained by the lipid depletion, can be rescued by a genetic and pharmacological approach that reduces the zinc accumulation and rescues the lipid levels in this mutant animal. Interestingly, the human ortholog of sbp-1, srebp-1, has been reported to play a role for virus infection, and zinc has been shown to inhibit the virus replication of multiple viruses. However, the mechanism through which zinc is acting is not well understood. These results suggest that the lipid regulation mediated by zinc may play a relevant role during mammalian virus infection.

Nicandra physalodes Extract Exerts Antiaging Effects in Multiple Models and Extends the Lifespan of Caenorhabditis elegans via DAF-16 and HSF-1.

The development of safe and effective therapeutic interventions is an important issue for delaying aging and reducing the risk of aging-related diseases. Chinese herbal medicines for the treatment of aging and other complex diseases are desired due to their multiple components and targets. Through screening for effects on lifespan of 836 Chinese herbal medicine extracts, Nicandra physalodes extract (HL0285) was found to exhibit lifespan extension activity in Caenorhabditis elegans (C. elegans). In further experiments, HL0285 improved healthspan, enhanced stress resistance, and delayed the progression of neurodegenerative diseases in C. elegans. Additionally, it ameliorated senescence in human lung fibroblasts (MRC-5 cells) and reversed liver function damage and reduced senescence marker levels in doxorubicin- (Dox-) induced aging mice. In addition, the longevity effect of HL0285 in C. elegans was dependent on the DAF-16 and HSF-1 signaling pathways, as demonstrated by the results of the mutant lifespan, gene level, and GFP level assays. In summary, we discovered that HL0285 had an antiaging effect in C. elegans, MRC-5 cells, and Dox-induced aging mice and deserves to be explored in the future studies on antiaging agents.

Longevity-promoting properties of ginger extract in Caenorhabditis elegans via the insulin/IGF-1 signaling pathway.

Ginger is a traditional medicinal and edible plant with multiple health-promoting properties. Nevertheless, the effects and potential mechanism of ginger on antiaging remain unknown. The aim of this study was to comprehend the antiaging effects and potential mechanism of ginger in Caenorhabditis elegans (C. elegans). The current findings showed that the lifespan of C. elegans was prolonged by 23.16% with the supplementation of 60 µg mL-1 ginger extract (GE), and the extension of lifespan was mainly attributed to the major bioactive compounds in GE, 6-, 8-, 10-gingerol and 6-, 8-, 10-shogaol. Subsequently, GE promoted healthy aging by improving nematode movement and attenuating lipofuscin accumulation, and enhanced stress tolerance by up-regulating the expression of stress-related genes and activating DAF-16 and SKN-1. Moreover, lifespan assays of relative mutants revealed that GE mediated extension of lifespan via the insulin/IGF-1 signaling (IIS) pathway. In summary, GE endowed nematodes (C. elegans) with longevity and stress resistance in an IIS pathway dependent manner.

Automatically tracking feeding behavior in populations of foraging C. elegans.

Caenorhabditis elegans feeds on bacteria and other small microorganisms which it ingests using its pharynx, a neuromuscular pump. Currently, measuring feeding behavior requires tracking a single animal, indirectly estimating food intake from population-level metrics, or using restrained animals. To enable large throughput feeding measurements of unrestrained, crawling worms on agarose plates at a single worm resolution, we developed an imaging protocol and a complementary image analysis tool called PharaGlow. We image up to 50 unrestrained crawling worms simultaneously and extract locomotion and feeding behaviors. We demonstrate the tool's robustness and high-throughput capabilities by measuring feeding in different use-case scenarios, such as through development, with genetic and chemical perturbations that result in faster and slower pumping, and in the presence or absence of food. Finally, we demonstrate that our tool is capable of long-term imaging by showing behavioral dynamics of mating animals and worms with different genetic backgrounds. The low-resolution fluorescence microscopes required are readily available in C. elegans laboratories, and in combination with our python-based analysis workflow makes this methodology easily accessible. PharaGlow therefore enables the observation and analysis of the temporal dynamics of feeding and locomotory behaviors with high-throughput and precision in a user-friendly system.

A small worm called C. elegans is constantly hungry. It spends all its time looking for food or eating. Hunger and environmental factors, like light, influence its feeding behavior. Studying these worms has helped scientists learn how feeding affects health, longevity, and aging. Feeding studies might also help scientists learn how the nervous system works and how it controls feeding. Most studies have used one of two approaches. Scientists may measure how much food a group of C. elegans eat by measuring food before and after it is offered to the worms. Or they restrain individual worms and measure the movement of a tube-like muscle, called the pharynx, which the animals use to vacuum up food. Restraining the worms can alter their behavior or brain activity, and studying group feeding habits may miss individual differences, so neither is optimal. Ideally, scientists could measure the feeding activity of many free-ranging worms, but because the movements of the pharynx are small, that too can be a challenge. Bonnard, Liu et al. developed a software tool that automatically detects and measures feeding behavior in a group of about 30 free-ranging C. elegans simultaneously. In the experiments, Bonnard, Liu et al. genetically engineered worms expressing a fluorescent protein in their pharynx, making it possible to measure its movements with a microscope. They used the microscope to capture images of 30-50 animals at a time as they foraged for food in a dish. Then, they used the software to analyze the data they collected. Over three days and five imaging sessions, Bonnard and Liu et al. tracked the feeding behavior of about 1,000 animals under different conditions. The experiments show that the pharynx grows rapidly during early worm development when the worms quadruple their length, but the rate of pharynx muscle contractions stays the same. They also showed the technique could measure feeding behaviors in animals with different genetic backgrounds, ages, or those engaged in behaviors like mating. The tool allows for larger and longer-term studies of worm feeding behaviors than previous approaches. Bonnard, Liu et al. made their software, called PharaGlow, available for use by other researchers. The tool may make feeding measurements a routine part of C. elegans studies. It will allow scientists to gain new insights into the role of feeding in a range of processes, including aging, fitness, mating, and overall health. Follow-up studies could determine if these findings are general strategies that also apply to other animals.