Wilm TP et al. (1999) Gene "Ballistic transformation of Caenorhabditis elegans."

Schnabel R, Demel P, Koop HU, Wilm TP, Schnabel H

[Gene, 1999]

A novel method to transform the nematode Caenorhabditis elegans is described. DNA coprecipitated with gold particles is shot at worms by means of a helium beam. Transformed worms are either identified by a dominant visible marker or selected by a conditional lethal system.

Zhang W et al. (2015) Chem Commun (Camb) "Elucidating the relationship between superoxide anion levels and lifespan using an enhanced two-photon fluorescence imaging probe."

Wang H, Zhang W, Wang X, Tang B, Li P, Huang F

[Chem Commun (Camb), 2015]

We report a new reversible fluorescent two-photon (TP) probe (PY-CA) with high TP absorption cross section and pH-independent fluorescence response, which allow monitoring of O2(-) fluxes dynamically, selectively and sensitively. The imaging results indicate that O2(-) at high levels can shorten the life of Caenorhabditis elegans.

Wang L et al. (2010) BMC Bioinformatics "Localizing triplet periodicity in DNA and cDNA sequences."

Wang L, Stein LD

[BMC Bioinformatics, 2010]

BACKGROUND: The protein-coding regions (coding exons) of a DNA sequence exhibit a triplet periodicity (TP) due to fact that coding exons contain a series of three nucleotide codons that encode specific amino acid residues. Such periodicity is usually not observed in introns and intergenic regions. If a DNA sequence is divided into small segments and a Fourier Transform is applied on each segment, a strong peak at frequency 1/3 is typically observed in the Fourier spectrum of coding segments, but not in non-coding regions. This property has been used in identifying the locations of protein-coding genes in unannotated sequence. The method is fast and requires no training. However, the need to compute the Fourier Transform across a segment (window) of arbitrary size affects the accuracy with which one can localize TP boundaries. Here, we report a technique that provides higher-resolution identification of these boundaries, and use the technique to explore the biological correlates of TP regions in the genome of the model organism C. elegans. RESULTS: Using both simulated TP signals and the real C. elegans sequence F56F11 as an example, we demonstrate that, (1) Modified Wavelet Transform (MWT) can better define the boundary of TP region than the conventional Short Time Fourier Transform (STFT); (2) The scale parameter (a) of MWT determines the precision of TP boundary localization: bigger values of a give sharper TP boundaries but result in a lower signal to noise ratio; (3) RNA splicing sites have weaker TP signals than coding region; (4) TP signals in coding region can be destroyed or recovered by frame-shift mutations; (5) 6 bp periodicities in introns and intergenic region can generate false positive signals and it can be removed with 6 bp MWT. CONCLUSIONS: MWT can provide more precise TP boundaries than STFT and the boundaries can be further refined by bigger scale MWT. Subtraction of 6 bp periodicity signals reduces the number of false positives. Experimentally-introduced frame-shift mutations help recover TP signal that have been lost by possible ancient frame-shifts. More importantly, TP signal has the potential to be used to detect the splice junctions in fully spliced mRNA sequence.

Yin H et al. (2015) Sci Rep "Tea polyphenols as an antivirulence compound Disrupt Quorum-Sensing Regulated Pathogenicity of Pseudomonas aeruginosa."

Wang H, Chu W, Zhuang X, Deng Y, Yin H, Liu W

[Sci Rep, 2015]

Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25~12.5mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection.

Liang S et al. (2016) Colloids Surf B Biointerfaces "A water-soluble and biocompatible polymeric nanolabel based on naphthalimide grafted poly(acrylic acid) for the two-photon fluorescence imaging of living cells and C. elegans."

Liang S, Yang F, Liu Y, Chen X, Fu T, Yan G

[Colloids Surf B Biointerfaces, 2016]

Polymeric nanoparticles (NPs) with two-photon (TP) activity were prepared by grafting a naphthalimide fluorophore onto poly(acrylic acid) to yield an amphiphilic polymer, which self-assembled in water. The NPs were characterized using various analytical techniques such as transmission electron microscopy, dynamic light scattering and spectroscopic measurements. The in vitro and in vivo biocompatibilities of the NPs were assessed by a cytotoxicity assay using HeLa cells and a feeding assay using Caenorhabditis elegans (C. elegans) as a small animal model, respectively. Finally, TP fluorescence imaging (FI) of living cells and C. elegans labelled with the NPs were observed by TP confocal microscopy. The experimental outcomes demonstrated that the NPs had sufficient water-dispersity and biocompatibility, had TP fluorescence activity, were resistant to pH variation and illumination, and were physically stable. TP FI revealed that the NPs could enter living cells and were primarily located in the cytoplasm. In addition, the NPs were ingested by C. elegans during the feeding process and were recognized and taken up by the active transport system of the intestinal cells. These findings indicated the feasibility of using the developed NPs as a nanolabel for TP FI. Moreover, with numerous modifiable carboxyl groups on its surface, the NPs could act as a platform to build multifunctional probes for potential applications in biosensing and assay labeling.

Jackstadt P et al. (1999) Mol Biochem Parasitol "Transformation of nematodes via ballistic DNA transfer."

Jackstadt P, Wilm TP, Zahner H, Hobom G

[Mol Biochem Parasitol, 1999]

Ballistic DNA transfer with tungsten or gold particles was originally used in plant cell transformation, but has been applied more recently in other organisms including mice and rabbits, and was also used for human DNA vaccination purposes.

Pooranachithra M et al. (2019) Life Sci "Unravelling the wound healing ability and mode of action of pyridine carboxamide oxime using Caenorhabditis elegans as potential prescreen wound model."

Pooranachithra M, Venkateswaran K, Sekhar DS, Gnanasekaran J, Balamurugan K, Deepa M, Prabhanand BJ

[Life Sci, 2019]

AIM: In the current scenario of ethical issues related to animal usage in research, the present study was intended to explore the proficient utility of nematode, Caenorhabditis elegans as wound model in preliminary screening of wound healing therapeutics. MAIN METHODS: In this study, a new wounding protocol and quantitative assessment strategies for various healing parameters [survival, Reactive Oxygen Species (ROS), calcium signals, F-actin dynamics, new collagen synthesis and wound induced anti-microbial peptides] were developed and used for preliminary screening of wound healing actives from natural sources. Wound healing ability of positive lead Tridax procumbens (TP) and its major phytocompounds [Octa decenoic acid (ODA), Pyridine carboxamide oxime, known as Nicotinamide (NA) and Dimethyl Benz[c]acridine (DMB)] were assessed using C. elegans wound model and cell lines scratch wound healing assay. Mode of action of active lead was elucidated using metabolome analysis coupled with MALDI-MS followed by molecular docking. KEY FINDINGS: From the four tested methanolic extracts, TP was chosen as positive lead compared to control, Benzalkonium chloride (BKC) based on survival and new collagen synthesis analyses. Results indicated that the wound healing ability of TP was majorly contributed by NA. Further, it was found that NA acts in chloromethyl nicotinamide derivative form by interacting with the known wound healing biomarker, glycogen synthase kinase 3 (GSK-3) to exert wound healing ability. SIGNIFICANCE: The study evidenced that C. elegans, could be a reliable wound model for high-throughput screening of wound healing actives and to identify their possible mode of action.

Zhang H et al. (2012) Water Res "Degradation of microcystin-LR in water by glow discharge plasma oxidation at the gas-solution interface and its safety evaluation."

Zhang H, Yang L, Huang Q, Wang X, Ke Z, Yu Z

[Water Res, 2012]

Microcystin-LR (MC-LR) is one of the most commonly found microcystins (MCs) in fresh water and it poses danger to human health due to its potential hepatotoxicity. In the present study, we employed a novel method by using discharge plasma taking place at the gas-solution interface in gas atmosphere to degrade MC-LR in aqueous solution. The initial degradation rate of MC-LR was fastest under acidic conditions (5.41 +/- 0.17 x 10(-3) mM min(-1) at pH 3.04) and decreased to 2.22 +/- 0.11 x 10(-3) mM min(-1) and 0.912 +/- 0.02 x 10(-3) mM min(-1) at pH 4.99 and 7.02, respectively. The effects of total soluble nitrogen (TN), total soluble phosphorus (TP) and natural organic matter (NOM) on the degradation efficiency were studied. The degradation rate was remarkably affected by TP and TN. Mass spectrometry was applied to identify the products of the reactions. Major degradation pathways are proposed according to the results of liquid chromatography/mass spectrometry (LC/MS) results. It suggests that the degradation of MC-LR is initiated via the attack of hydroxyl radicals on the conjugated carbon double bonds of Adda and on the benzene ring of Adda. Finally, the toxicity of intermediates or end-products from MC-LR degraded by this method was assessed using Caenorhabditis elegans. Our findings demonstrates that discharge plasma oxidation is a promising technology for degradation and removal of MC-LR and it may lead us to a new route to efficient treatment of other cyanotoxins from aqueous solutions.

Salas AL et al. (2016) Phytomedicine "Biological activities of polyphenols-enriched propolis from Argentina arid regions."

Salas AL, Isla MI, Alberto MR, Cuello AS, Zampini IC, Schmeda-Hirschmann G, Rios JL, Maldonado L

[Phytomedicine, 2016]

BACKGROUND: Propolis is a bioactive natural product collected by honeybees (Apis mellifera) from plant sources. PURPOSE: This study was undertaken to determine the effect of propolis extracts from arid region of Argentina, on the activity/expression of pro-inflammatory enzymes, and as potential free radical scavenger, antifungal and anthelmintic agent as well as to get a first insight into the polyphenolic profile of the active fractions. STUDY DESIGN/METHODS: Two propolis samples were collected in different time from hives located in Tucuman, Argentina. They are representative of the collection time of the raw material for phytotherapeutical purposes. Ethanolic extracts from both propolis were obtained. The PEEs were analyzed for total polyphenol (TP), non-flavonoid phenols (NFP) and flavonoid (FP) content followed by HPLC-DAD analysis and identification of components by HPLC-MS/MS(n). The potentiality as anti-inflammatory (LOX, COX, iNOS enzymes), antioxidant, antifungal and nematicidal was determined. RESULTS: PEEs contain high levels of TP, NFP and FP, including cinnamic acid, caffeic acid prenyl ester, caffeoyl dihydrocaffeate and caffeic acid 3,4-dihydroxyphenethyl ester, liquiritigenin, 2',4'-dihydroxychalcone and 2',4'-dihydroxy-3'-methoxychalcone. The PEEs in vitro reduced the activity of LOX and COX-2. Pretreatment of RAW 264.7 cells with PEEs before the induction of inflammatory state, inhibited NO overproduction and the iNOS protein expression was significantly decreased. The PEEs exhibited antioxidant, antifungal (Candida sp.) and nematicidal effect (C. elegans). CONCLUSION: These findings show the potential use of characterized PEEs from arid regions of Argentina as phytomedicine.

van Krugten J et al. (2022) Commun Biol "A local interplay between diffusion and intraflagellar transport distributes TRPV-channel OCR-2 along C. elegans chemosensory cilia."

VAN Krugten J, Danne N, Peterman EJG

[Commun Biol, 2022]

To survive, Caenorhabditis elegans depends on sensing soluble chemicals with transmembrane proteins (TPs) in the cilia of its chemosensory neurons. Cilia rely on intraflagellar transport (IFT) to facilitate the distribution of cargo, such as TPs, along the ciliary axoneme. Here, we use fluorescence imaging of living worms and perform single-molecule tracking experiments to elucidate the dynamics underlying the ciliary distribution of the sensory TP OCR-2. Quantitative analysis reveals that the ciliary distribution of OCR-2 depends on an intricate interplay between transport modes that depends on the specific location in the cilium: in dendrite and transition zone, directed transport is predominant. Along the cilium motion is mostly due to normal diffusion together with a small fraction of directed transport, while at the ciliary tip subdiffusion dominates. These insights in the role of IFT and diffusion in ciliary dynamics contribute to a deeper understanding of ciliary signal transduction and chemosensing.