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.

Davis, Kristen et al. (2015) International Worm Meeting "The appetite control circuit in C. elegans."

You, Young-jai, Davis, Kristen

[International Worm Meeting, 2015]

Satiety quiescence is a behavioral state defined as a lack of movement or feeding following satiation. ASI is important for worms to enter satiety quiescence. We found the nutrients directly activate ASI. The nutrient rich stimulus we use in the lab is Luria broth (LB) and we are working to identify the active component by testing individual components of LB. Feeding is stimulated or suppressed depending not only on metabolic needs but also on environmental cues. To understand how feeding is controlled by environmental cues, we treated worms with nutrients mixed with noxious stimuli such as a high concentration of NaCl (4 M). 1 We found that these noxious stimuli override the ASI activation by nutrients, suggesting feeding, a potential result after sensing nutrients via ASI, can be suppressed in the presence of noxious stimuli. Furthermore, ASI suppression by noxious stimuli is entirely dependent on ASH function, a pair of neurons required for sensation of noxious stimuli. In an ASH genetic ablation background, ASI continue to respond to LB in the presence or absence of noxious stimuli. We believe there is a circuit between ASH, ASI, and an interneuron pair, AIA, which regulates ASI activation to nutrients. Our behavioral data show in an AIA genetic ablation background and an ASH genetic ablation background that satiety quiescence is enhanced when compared to concurrent controls, suggesting the signals from these neuron pairs inhibit ASI and satiety quiescence when they are intact. Recent work by others has identified a potential circuit between ASH and ASI that included three other neuron pairs RIM/RIC and ADF, although this circuit was not tested in the context of feeding or nutrient availability. 21. Chatzigeorgiou M, Bang S, Hwang SW, Schafer WR. tmc-1 encodes a sodium-sensitive channel required for salt chemosensation in C. elegans. Nature. 2013;494(7435):95-9. doi:10.1038/nature11845.2. Guo M, Wu T-H, Song Y-X, et al. Reciprocal inhibition between sensory ASH and ASI neurons modulates nociception and avoidance in Caenorhabditis elegans. Nat Commun. 2015;6:1-13. doi:10.1038/ncomms6655.

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.

Tabuse Y et al. (1994) Worm Breeder's Gazette "The tpa-1 Gene Encodes Two Forms of a Protein Kinase C Homolog."

Tabuse Y, Miwa J, Sano T

[Worm Breeder's Gazette, 1994]

The tpa-l gene encodes two forms of a protein kinase C homolog Yo Tabuse, Tohru Sano, and Johji Miwa NEC Fundamental Research Laboratories, Tsukuba, Ibaraki 305, Japan. Typical tumor-promoting phorbol esters (TPA and PDD) cause severe disorders in the growth and behavior of C. elegans. The tpa-l gene, which mediates the action of the agents, encodes a protein kinase C (PKC) homolog. The tpa-l gene consists of eleven exons and spans a genomic region of about 20 kb. Two mRNA species, 2.8 kb and 2.4 kb, are transcribed from the tpa-l locus and both are trans-spliced to SL1. The former contains all the eleven exons and codes for a protein of 80 kDa (TPA-lA); on the other hand, the latter lacks the first four exons and codes for a 65-kDa protein (TPA-lB) without some 150 amino acids at the amino-terminal portion of TPA-lA (Sano et al. C. elegans meeting '93, see Figure). In order to examine whether the two mRNA species are produced by two alternate promoters, we have tried to rescue a TPA- resistant mutant strain, MJ563, by microinjecting genomic fragments of the tpa-l gene, variously lacking its 5' region. Microinjection of plasmid constructs of these fragments showed rescuing activity. One of these rescuing constTucts, pSK14, contained a fragment covering only about 1 kb upstream of the 5th exon through the end of tpa-l, indicating that there is another promoter within 1 kb upstream of the 5th exon for the 2.4-kb mRNA. The result also shows that TPA-lB is sufficient to confer TPA-sensitivity on C. elegans. We are now examining tissue expression patterns of the 2.8-kb and 2.4-kb mRNAs with tpa-l-lacZ fusions to ask whether there are any differences in the distribution of these two mRNAs.

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.