Gui-Sheng Wu

Aspirin extends the lifespan of Caenorhabditis elegans via AMPK and DAF-16/FOXO in dietary restriction pathway.

Aspirin has been revealed to have many beneficial effects for health since it was discovered as a nonsteroidal anti-inflammatory drug (NSAID) to treat pain and inflammation. Here, we investigated the molecular mechanism of aspirin on the lifespan extension of Caenorhabditis elegans. Our results showed that aspirin could extend the lifespan of C. elegans, and increase its health span and stress resistance. The extension of lifespan by aspirin requires DAF-16/FOXO, AMPK, and LKB1, but not SIR-2.1. Aspirin could not extend the lifespan of the mutants of eat-2, clk-1, and isp-1. Aspirin could marginally extend the lifespan of long-live insulin-like receptor mutant daf-2(e1370) III. Taken together, aspirin might act through a dietary restriction-like mechanism, via increasing the AMP:ATP ratio and activating LKB1, subsequently activating AMPK, which stimulates DAF-16 to induce downstream effects through a DAF-16 translocation independent manner.

Drug Absorption Efficiency in Caenorhbditis elegans Delivered by Different Methods

Background Caenorhbditis elegans has being vigorously used as a model organism in many research fields and often accompanied by administrating with various drugs. The methods of delivering drugs to worms are varied from one study to another, which make difficult in comparing results between studies. Methodology/Principal Findings We evaluated the drug absorption efficiency in C. elegans using five frequently used methods with resveratrol with low aqueous solubility and water-soluble 5-Fluoro-2′-deoxyuridine (FUDR) as positive compounds. The drugs were either applied to the LB medium with bacteria OP50, before spreading onto Nematode Growth Medium (NGM) plates (LB medium method), or to the NGM with live (NGM live method) or dead bacteria (NGM dead method), or spotting the drug solution to the surface of plates directly (spot dead method), or growing the worms in liquid medium (liquid growing method). The concentration of resveratrol and FUDR increased gradually within C. elegans and reached the highest during 12 hours to one day and then decreased slowly. At the same time point, the higher the drug concentration, the higher the metabolism rate. The drug concentrations in worms fed with dead bacteria were higher than with live bacteria at the same time point. Consistently, the drug concentration in medium with live bacteria decreased much faster than in medium with dead bacteria, reach to about half of the original concentration within 12 hours. Conclusion Resveratrol with low aqueous solubility and water-soluble FUDR have the same absorption and metabolism pattern. The drug metabolism rate in worms was both dosage and time dependent. NGM dead method and liquid growing method achieved the best absorption efficiency in worms. The drug concentration within worms was comparable with that in mice, providing a bridge for dose translation from worms to mammals.

Chlorogenic Acid Extends the Lifespan of Caenorhabditis elegans via Insulin/IGF-1 Signaling Pathway

Coffee and tea, two of the most popular drinks around the world, share many in common from chemical components to beneficial effects on human health. One of their shared components, the polyphenols, most notably chlorogenic acid (CGA), was supposed to account for many of the beneficial effects on ameliorating diseases occurred accompanying people aging, such as the antioxidant effect and against diabetes and cardiovascular disease. CGA is also present in many traditional Chinese medicines. However, the mechanism of these effects was vague. The aging signaling pathways were conservative from yeast and worms to mammals. So, we tested if CGA had an effect on aging in Caenorhabditis elegans. We found that CGA could extend the lifespan of C. elegans by up to 20.1%, delay the age-related decline of body movement, and improve stress resistance. We conducted genetic analysis with a series of worm mutants and found that CGA could extend the lifespan of the mutants of eat-2, glp-1, and isp-1, but not of daf-2, pdk-1, akt-1, akt-2, sgk-1, and clk-1. CGA could activate the FOXO transcription factors DAF-16, HSF-1, SKN-1, and HIF-1, but not SIR-2.1. Taken together, CGA might extend the lifespan of C. elegans mainly via DAF-16 in insulin/IGF-1 signaling pathway.

Current Perspective in the Discovery of Anti-aging Agents from Natural Products

Aging is a process characterized by accumulating degenerative damages, resulting in the death of an organism ultimately. The main goal of aging research is to develop therapies that delay age-related diseases in human. Since signaling pathways in aging of Caenorhabditis elegans (C. elegans), fruit flies and mice are evolutionarily conserved, compounds extending lifespan of them by intervening pathways of aging may be useful in treating age-related diseases in human. Natural products have special resource advantage and with few side effect. Recently, many compounds or extracts from natural products slowing aging and extending lifespan have been reported. Here we summarized these compounds or extracts and their mechanisms in increasing longevity of C. elegans or other species, and the prospect in developing anti-aging medicine from natural products.

Effect of nigranoic acid on Ca2+ influx and its downstream signal mechanism in NGF-differentiated PC12 cells

ETHNOPHARMACOLOGICAL RELEVANCEnSchisandra chinensis has a long history of use as a famous traditional Chinese medicine. The plants of genus Schisandra, especially Schisandra neglecta, Schisandra rubriflora, and Schisandra sphaerandra are used in the same way as Schisandra chinensis in the folk medicine to treat insomnia, fatigue, increasing intelligence, and tranquilizing. Many studies showed that lignans were the major active components of Schisandra genus, whereas the bioactivity of abundant triterpenoids in Schisandra genus, such as nigranoic acid (SBB1, 3,4-secocycloartene triterpenoid), has not been examined yet in neuropathology.nnnMATERIALS AND METHODSnAfter treating with SBB1, intracellular Ca(2+) concentration was analyzed by Ca(2+) fluorescent indicator (Fluo-4 AM) in NGF-differentiated PC12 cells. Intracellular nitric oxide (NO) level was analyzed using NO fluorescent indicator (DAF-FM). The expression of extracellular signal regulated kinase 1 and 2 (ERK1/2) was analyzed by western blotting, and the temporal mRNA for BDNF and c-fos was analyzed using reverse transcription quantitative PCR.nnnRESULTnWe found that SBB1 induced Ca(2+) influx in a time- and concentration-dependent manner, which was significantly attenuated in Ca(2+) free media. SBB1 promoted the intracellular NO production which depended on increasing cytoplasmic Ca(2+) level. Moreover, SBB1 stimulated activation of ERK1/2 through Ca(2+)-CaMKII pathway. In addition, we found that SBB1 increased the expression of BDNF and c-fos mRNA.nnnCONCLUSIONnThese results suggest that SBB1 is able to promote NO production and stimulate phosphorylation of ERK1/2 through Ca(2+) influx, further impact expression of BDNF and c-fos, which provides evidence for the effects of SBB1 that may be benefit to enhance mental and intellectual functions.

Aspirin increases metabolism through germline signalling to extend the lifespan of Caenorhabditis elegans

Aspirin is a prototypic cyclooxygenase inhibitor with a variety of beneficial effects on human health. It prevents age-related diseases and delays the aging process. Previous research has shown that aspirin might act through a dietary restriction-like mechanism to extend lifespan. To explore the mechanism of action of aspirin on aging, we determined the whole-genome expression profile of Caenorhabditis elegans treated with aspirin. Transcriptome analysis revealed the RNA levels of genes involved in metabolism were primarily increased. Reproduction has been reported to be associated with metabolism. We found that aspirin did not extend the lifespan or improve the heat stress resistance of germline mutants of glp-1. Furthermore, Oil Red O staining showed that aspirin treatment decreased lipid deposition and increased expression of lipid hydrolysis and fatty acid β-oxidation-related genes. The effect of germline ablation on lifespan was mainly mediated by DAF-12 and DAF-16. Next, we performed genetic analysis with a series of worm mutants and found that aspirin did not further extend the lifespans of daf-12 and daf-16 single mutants, glp-1;daf-12 and glp-1;daf-16 double mutants, or glp-1;daf-12;daf-16 triple mutants. The results suggest that aspirin increase metabolism and regulate germline signalling to activate downstream DAF-12 and DAF-16 to extend lifespan.

Brain-wide map of projections from mice ventral subiculum

The hippocampal formation plays a critical role in episodic memory formation and spatial navigation. Within the hippocampus, the subiculum is considered to be a hub connecting the hippocampal formation to the remainder of the brain. There are functional differences between the dorsal and ventral part of subiculum, while the ventral subiculum (vSub) plays a role in anxiety, stress and emotion. In the present study, we examined the projection of the ventral subiculum to the whole brain in mice by using a modified herpes simplex virus 1 strain H129 with an inserted fluorescent protein gene. In our experiments, the modified H129 transits the primary-order, second-order, and third-order neuronal projections at 36-44, 52-60 and 68-76h after inoculation in mice, respectively. Our data revealed that vSub directly projects to the medial entorhinal cortex, amygdalohippocampal area, anterodorsal thalamic nucleus, medial hypothalamus, supramammillary nucleus, medial septal nucleus and adjacent diagonal band, the connections between median raphe nucleus and interpeduncular nucleus in brain stem, while ventral prefrontal cortex, laterodorsal tegmental nucleus and locus coeruleus receives second-order projections from vSub. Our data would help further understanding the functional connections of vSub with other brain regions.

Quantitative proteomics analysis of Caenorhabditis elegans upon germ cell loss

The abrogation of the germ cells in Caenorhabditis elegans (C. elegans) by either genetic means or cell ablation results in about 60% increase of longevity. Upon the inhibition of germline stem cell proliferation, certain signaling molecules inhibit the target of rapamycin (TOR), activate the transcription factors including DAF-16, DAF-12, and PHA-4, leading to altered fatty acid lipolysis, autophagy, stress resistance, and the extended lifespan. But the exact cascades and interactions of those signaling pathways are still obscure. To understand how the reproductive system affects aging at the protein level, we determined the protein expression profile of the long-lived temperature-sensitive mutant glp-1(e2141) and wild-type N2 using isobaric tags for relative and absolute quantitation (iTRAQ) technology. Our results showed that the abundance of proteins relevant to transcription, RNA processing, translation, protein folding, and proteolytic process were decreased, while collagen proteins and proteins involved in detoxification and innate immune responses were increased in C. elegans glp-1 mutant, these alterations of protein abundance might attenuate protein metabolism and enhance immune response and stress resistance, and finally contribute to germline-mediated longevity.nnnBIOLOGICAL SIGNIFICANCEnThis study provides an overview of the altered protein expression upon germline ablation. Germ-cell loss results in decreased abundance of proteins involved in protein synthesis and breakdown, and increased abundance of proteins involved in detoxification and immune response, suggesting that protein synthesis and metabolism might be attenuated, while detoxification and immune responses might be increased. The altered protein abundance might result in physiological adaptations that contribute to extended longevity in germline-deficient C. elegans. This study brings new light on the role of reproductive control of lifespan.

Metabolomic signature associated with reproduction-regulated aging in Caenorhabditis elegans

In Caenorhabditis elegans (C. elegans), ablation of germline stem cells (GSCs) leads to infertility, which extends lifespan. It has been reported that aging and reproduction are both inextricably associated with metabolism. However, few studies have investigated the roles of polar small molecules metabolism in regulating longevity by reproduction. In this work, we combined the nuclear magnetic resonance (NMR) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) to profile the water-soluble metabolome in C. elegans. Comparing the metabolic fingerprint between two physiological ages among different mutants, our results demonstrate that aging is characterized by metabolome remodeling and metabolic decline. In addition, by analyzing the metabolic profiles of long-lived germline-less glp-1 mutants, we discovered that glp-1 mutants regulate the levels of many age-variant metabolites to attenuate aging, including elevated concentrations of the pyrimidine and purine metabolism intermediates and decreased concentrations of the citric acid cycle intermediates. Interestingly, by analyzing the metabolome of daf-16;glp-1 double mutants, our results revealed that some metabolic exchange contributing to germline-mediated longevity was mediated by transcription factor FOXO/DAF-16, including pyrimidine metabolism and the TCA cycle. Based on a comprehensive metabolic analysis, we provide novel insight into the relationship between longevity and metabolism regulated by germline signals in C. elegans

Cloning and characterization of a novel apolipoprotein gene, apolipoprotein AV, in tree shrews

Apolipoprotein AV (apoAV) modulates plasma triglyceride levels, which is an independent risk factor for cardiovascular disease. ApoAV is also involved in atherosclerosis lesion formation. In order to systematically evaluate the apolipoprotein-related gene profile in tree shrew, a model for its insusceptibility to atherosclerosis, we performed apoAV cloning and characterization. The full-length cDNA of apoAV was identified using SMART-RACE. ApoAV cDNA sequence revealed two transcripts, 1,948 and 1,397 base pairs, due to alternative polyadenylation. These two transcripts share the same open reading frame (ORF), which encodes a 369-amino acid protein with high identity to human apoAV (75xa0%), including a 23-amino acid N-terminal signal peptide. ApoAV is expressed exclusively in the liver. Mature apoAV was expressed in E. coli BL21(DE3) and purified by Ni-chelated resin. Lipoprotein lipase activity was significantly stimulated by this recombinant protein. The full-length ORF of apoAV was cloned into pDsRed-monomer-N1 vector with a red fluorescent protein tag and was primarily localized in cytoplasm of hepG2 cells. The successful cloning, expression and localization of apoAV in tree shrew has laid down the foundation for further investigation on its structure and functions.