Qiao L et al. (2008) Mol Brain "Lysosomal enzyme cathepsin D protects against alpha-synuclein aggregation and toxicity."

Parks R, Peng L, Crimmins S, Wilson S, Schneider L, Standaert DG, Shacka JJ, Zhou Y, Caldwell GA, Lu Y, Walls KC, Crabtree D, Uchiyama Y, Liang Q, Yacoubian TA, Xie ZL, Zhang J, Caldwell KA, Speake LD, Iwatsubo T, Qiao L, Hamamichi S, Roth KA

[Mol Brain, 2008]

-synuclein (-syn) is a main component of Lewy bodies (LB) that occur in many neurodegenerative diseases, including Parkinson's disease (PD), dementia with LB (DLB) and multi-system atrophy. -syn mutations or amplifications are responsible for a subset of autosomal dominant familial PD cases, and overexpression causes neurodegeneration and motor disturbances in animals. To investigate mechanisms for -syn accumulation and toxicity, we studied a mouse model of lysosomal enzyme cathepsin D (CD) deficiency, and found extensive accumulation of endogenous -syn in neurons without overabundance of -syn mRNA. In addition to impaired macroautophagy, CD deficiency reduced proteasome activity, suggesting an essential role for lysosomal CD function in regulating multiple proteolytic pathways that are important for -syn metabolism. Conversely, CD overexpression reduces -syn aggregation and is neuroprotective against -syn overexpression-induced cell death in vitro. In a C. elegans model, CD deficiency exacerbates -syn accumulation while its overexpression is protective against -syn-induced dopaminergic neurodegeneration. Mutated CD with diminished enzymatic activity or overexpression of cathepsins B (CB) or L (CL) is not protective in the worm model, indicating a unique requirement for enzymatically active CD. Our data identify a conserved CD function in -syn degradation and identify CD as a novel target for LB disease therapeutics.

Zhang L et al. (2019) Anal Chem "Interaction-Transferable Graphene-Isolated Superstable AuCo Nanocrystal-Enabled Direct Cyanide Capture."

Xu Y, Liao Y, Li Z, Li S, Zheng Z, Tan W, Chen Z, Zhang J, Liu Z, Yi H, Zhang L

[Anal Chem, 2019]

Noble metals with strong plasmons have been widely used as enhancement substrates for molecule identification. However, cyanide, a toxic and important signaling molecule with a corrosive nature to noble metals, makes direct recognition challenging. Herein a novel superstable magnetic graphene-isolated AuCo nanocrystal (MACG) has been designed. Such graphene isolation enables superior stability without corrosion. Moreover, unexpectedly, although graphene isolated direct contact between Au and cyanide, their interaction was transferable and remained, which gifted MACGs direct cyanide capture capability with no specific ligands needed. Density functional theory calculations and natural bond orbital analysis indicated that the graphene isolation only slightly affected the charge transfer and that a relatively strong interaction was maintained between Au and cyanide. MACGs were utilized for efficient cyanide capture and clearance in various hydrologic environments and sensitive in vivo cyanide capture in C. elegans infected with P. aeruginosa, a pathogen with cyanide as the biomarker, indicating promise for various applications.

Wohlschlager T et al. (2014) Proc Natl Acad Sci U S A "Methylated glycans as conserved targets of animal and fungal innate defense."

Kunzler M, Wohlschlager T, Grassi P, Dell A, Butschi A, Schmieder SS, Gauss R, Titz A, Haslam SM, Sutov G, Aebi M, Hauck D, Hengartner MO, Knobel M

[Proc Natl Acad Sci U S A, 2014]

Effector proteins of innate immune systems recognize specific non-self epitopes. Tectonins are a family of -propeller lectins conserved from bacteria to mammals that have been shown to bind bacterial lipopolysaccharide (LPS). We present experimental evidence that two Tectonins of fungal and animal origin have a specificity for O-methylated glycans. We show that Tectonin 2 of the mushroom Laccaria bicolor (Lb-Tec2) agglutinates Gram-negative bacteria and exerts toxicity toward the model nematode Caenorhabditis elegans, suggesting a role in fungal defense against bacteria and nematodes. Biochemical and genetic analysis of these interactions revealed that both bacterial agglutination and nematotoxicity of Lb-Tec2 depend on the recognition of methylated glycans, namely O-methylated mannose and fucose residues, as part of bacterial LPS and nematode cell-surface glycans. In addition, a C. elegans gene, termed samt-1, coding for a candidate membrane transport protein for the presumptive donor substrate of glycan methylation, S-adenosyl-methionine, from the cytoplasm to the Golgi was identified. Intriguingly, limulus lectin L6, a structurally related antibacterial protein of the Japanese horseshoe crab Tachypleus tridentatus, showed properties identical to the mushroom lectin. These results suggest that O-methylated glycans constitute a conserved target of the fungal and animal innate immune system. The broad phylogenetic distribution of O-methylated glycans increases the spectrum of potential antagonists recognized by Tectonins, rendering this conserved protein family a universal defense armor.

Ramli NS et al. (2012) PLoS One "The effect of environmental conditions on biofilm formation of Burkholderia pseudomallei clinical isolates."

Vadivelu J, Nathan S, Eng Guan C, Ramli NS

[PLoS One, 2012]

Burkholderia pseudomallei, a Gram-negative saprophytic bacterium, is the causative agent of the potentially fatal melioidosis disease in humans. In this study, environmental parameters including temperature, nutrient content, pH and the presence of glucose were shown to play a role in in vitro biofilm formation by 28 B. pseudomallei clinical isolates, including four isolates with large colony variants (LCVs) and small colony variants (SCVs) morphotypes. Enhanced biofilm formation was observed when the isolates were tested in LB medium, at 30 C, at pH 7.2, and in the presence of as little as 2 mM glucose respectively. It was also shown that all SVCs displayed significantly greater capacity to form biofilms than the corresponding LCVs when cultured in LB at 37 C. In addition, octanoyl-homoserine lactone (C(8)-HSL), a quorum sensing molecule, was identified by mass spectrometry analysis in bacterial isolates referred to as LCV CTH, LCV VIT, SCV TOM, SCV CTH, 1 and 3, and the presence of other AHL's with higher masses; decanoyl-homoserine lactone (C(10)-HSL) and dodecanoyl-homoserine lactone (C(12)-HSL) were also found in all tested strain in this study. Last but not least, we had successfully acquired two Bacillus sp. soil isolates, termed KW and SA respectively, which possessed strong AHLs degradation activity. Biofilm formation of B. pseudomallei isolates was significantly decreased after treated with culture supernatants of KW and SA strains, demonstrating that AHLs may play a role in B. pseudomallei biofilm formation.

Carvalho A et al. (2011) PLoS One "Acute drug treatment in the early C. elegans embryo."

Zanin E, Carvalho A, Olson SK, Groisman A, Zhang K, Gutierrez E, Oegema K, Desai A, Noble LB

[PLoS One, 2011]

Genetic and genome-wide RNAi approaches available in C. elegans, combined with tools for visualizing subcellular events with high-resolution, have led to increasing adoption of the early C. elegans embryo as a model for mechanistic and functional genomic analysis of cellular processes. However, a limitation of this system has been the impermeability of the embryo eggshell, which has prevented the routine use of small molecule inhibitors. Here, we present a method to permeabilize and immobilize embryos for acute inhibitor treatment in conjunction with live imaging. To identify a means to permeabilize the eggshell, we used a dye uptake assay to screen a set of 310 candidate genes defined by a combination of bioinformatic criteria. This screen identified 20 genes whose inhibition resulted in >75% eggshell permeability, and 3 that permeabilized embryos with minimal deleterious effects on embryo production and early embryonic development. To mount permeabilized embryos for acute drug addition in conjunction with live imaging, we combined optimized inhibition of one of these genes with the use of a microfabricated chamber that we designed. We demonstrate that these two developments enable the temporally controlled introduction of inhibitors for mechanistic studies. This method should also open new avenues of investigation by allowing profiling and specificity-testing of inhibitors through comparison with genome-wide phenotypic datasets.

Zheng SQ et al. (2013) PLoS One "Drug absorption efficiency in Caenorhbditis elegans delivered by different methods."

Wu GS, Li GP, Ding AJ, Luo HR, Zheng SQ

[PLoS One, 2013]

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.

Bhuvanesh S et al. (2010) J Ind Microbiol Biotechnol "Production and single-step purification of Brugia malayi abundant larval transcript (ALT-2) using hydrophobic interaction chromatography."

Arunkumar C, Ramalingam S, Kaliraj P, Bhuvanesh S

[J Ind Microbiol Biotechnol, 2010]

Abundant larval transcript (ALT), a novel filarial protein, has been shown to have great potential as a vaccine in the prevention of human lymphatic filariasis. In this study, we report a method for the production of recombinant ALT-2 protein, expressed in the cytoplasm of bacterium Escherichia coli in soluble form and purification in a single step using hydrophobic interaction chromatography (HIC). Fermentation was done by continuous fed-batch methodology with dissolved oxygen (DO)-controlled feed addition. The culture was induced with 1mM isopropyl--D: -thiogalactopyranoside (IPTG). Up to 9g/l dry cell weight (DCW) of biomass was obtained from 1.6l of Luria-Bertani (LB) broth in a bench-scale reactor. Around 200mg/l of purified ALT-2 with a yield of about 60% was obtained. This is almost a 2.5-fold increase in final protein yield compared to purification using immobilized metal affinity chromatography (IMAC).

Zarse K et al. (2008) PLoS One "Antidepressants of the serotonin-antagonist type increase body fat and decrease lifespan of adult Caenorhabditis elegans."

Zarse K, Ristow M

[PLoS One, 2008]

It was recently suggested that specific antidepressants of the serotonin-antagonist type, namely mianserin and methiothepin, may exert anti-aging properties and specifically extend lifespan of the nematode C.elegans by causing a state of perceived calorie restriction (Petrascheck M, Ye X, Buck LB: An antidepressant that extends lifespan in adult Caenorhabditis elegans; Nature, Nov 22, 2007;450(7169):553-6, PMID 18033297). Using the same model organism, we instead observe a reduction of life expectancy when employing the commonly used, standardized agar-based solid-phase assay while applying the same or lower concentrations of the same antidepressants. Consistent with a well-known side-effect of these compounds in humans, antidepressants not only reduced lifespan but also increased body fat accumulation in C. elegans reflecting the mammalian phenotype. Taken together and in conflict with previously published findings, we find that antidepressants of the serotonin-antagonist type not only promote obesity, but also decrease nematode lifespan.

Higurashi S et al. (2023) Elife "Bacterial diet affects the age-dependent decline of associative learning in Caenorhabditis elegans."

Tanaka M, Aleogho BM, Nakano S, Noma K, Tsukada S, Park JH, Al-Hebri Y, Mori I, Higurashi S

[Elife, 2023]

The causality and mechanism of dietary effects on brain aging are still unclear due to the long time scales of aging. The nematode <i>Caenorhabditis elegans</i> has contributed to aging research because of its short lifespan and easy genetic manipulation. When fed the standard laboratory diet, <i>Escherichia coli</i>, <i>C. elegans</i> experiences an age-dependent decline in temperature-food associative learning, called thermotaxis. To address if diet affects this decline, we screened 35 lactic acid bacteria as alternative diet and found that animals maintained high thermotaxis ability when fed a clade of <i>Lactobacilli</i> enriched with heterofermentative bacteria. Among them, <i>Lactobacill</i>us <i>reuteri</i> maintained the thermotaxis of aged animals without affecting their lifespan and motility. The effect of <i>Lb. reuteri</i> depends on the DAF-16 transcription factor functioning in neurons. Furthermore, RNA sequencing analysis revealed that differentially expressed genes between aged animals fed different bacteria were enriched with DAF-16 targets. Our results demonstrate that diet can impact brain aging in a <i>daf-16</i>-dependent manner without changing the lifespan.

Bogaerts A et al. (2010) Biol Direct "Proteome changes of Caenorhabditis elegans upon a Staphylococcus aureus infection."

Verleyen P, Temmerman L, Schoofs L, Beets I, Bogaerts A

[Biol Direct, 2010]

BACKGROUND: The success of invertebrates throughout evolution is an excellent illustration of the efficiency of their defence strategies. Caenorhabditis elegans has proven to be an appropriate model for transcriptome studies of host-pathogen interactions. The aim of this paper is to complement this knowledge by investigating the worm's response to a Staphylococcus aureus infection through a 2-dimensional differential proteomics approach. RESULTS: Different types of growth media in combination with either E. coli OP50 or Staphylococcus aureus were tested for an effect on the worm's lifespan. LB agar was chosen and C. elegans samples were collected 1 h, 4 h, 8 h and 24 h post S. aureus infection or E. coli incubation. Proteomics analyses resulted in the identification of 130 spots corresponding to a total of 108 differentially expressed proteins. CONCLUSIONS: Exploring four time-points discloses a dynamic insight of the reaction against a gram-positive infection at the level of the whole organism. The remarkable upregulation after 8 h and 24 h of many enzymes involved in the citric acid cycle might illustrate the cost of fighting off an infection. Intriguing is the downregulation of chaperone molecules, which are presumed to serve a protective role. A comparison with a similar experiment in which C. elegans was infected with the gram-negative Aeromonas hydrophila reveals that merely 9% of the identified spots, some of which even exhibiting an opposite regulation, are present in both studies. Hence, our findings emphasise the complexity and pathogen-specificity of the worm's immune response and form a firm basis for future functional research. REVIEWERS: This article was reviewed by Itai Yanai, Dieter Wolf and Torben Luebke (nominated by Walter Lutz).