Knox, Jessica et al. (2021) International Worm Meeting "A Survey of the Kinome Pharmacopeia Reveals Multiple Scaffolds and Targets for the Development of Novel Anthelmintics"

Knox, Jessica, Carmona-Negron, Jose A., Roy, Peter J., Zuercher, William, Linossi, Edmond M., Joly, Nicolas, Pintard, Lionel, Jura, Natalia

[International Worm Meeting, 2021]

Over one billion people are currently infected with a parasitic nematode. Symptoms can include anemia, malnutrition, developmental delay, and in severe cases, death. Resistance is emerging to the anthelmintics currently used to treat nematode infection, prompting the need to develop new anthelmintic drugs. Towards this end, we identified a set of kinases that may be targeted in a nematode-selective manner. We first screened 2040 inhibitors of vertebrate kinases for those that impair the model nematode Caenorhabditis elegans. By determining whether the terminal phenotype induced by each kinase inhibitor matched that of the predicted target mutant in C. elegans, we identified 17 druggable nematode kinase targets. Of these, we found that nematode EGFR, MEK1, and PLK1 kinase orthologs have diverged from vertebrates in key residues within their drug-binding pocket. For each of these targets, we identified small molecule scaffolds that may be further modified to develop nematode-selective inhibitors. Nematode EGFR, MEK1, and PLK1 therefore represent important targets for the development of new anthelmintic medicines.

Gallotta I et al. (2010) Neuronal Development, Synaptic Function and Behavior, Madison, WI "Cell Specific Knock-down of Gene Function in Targeted C. elegans Neurons"

D'Orta M, Vitale M, Castro S, Esposito G, Hilliard M A, Di Schiavi E, Gallotta I

[Neuronal Development, Synaptic Function and Behavior, Madison, WI, 2010]

An important aspect in the study of gene function is the possibility to dissect the role exerted by a gene of interest selectively in specific cells or groups of cells. In C. elegans the available approaches are time consuming and largely restricted to non-essential genes for which mutants are available. We have developed a simple reverse genetics approach to reduce the function of specific genes in chosen C. elegans neurons (Esposito et al., 2007). By expressing sense and antisense RNA corresponding to a gene of interest under cell-specific promoters, we obtain an efficient, heritable and cell autonomous knock-down of the targeted gene function in the specific neurons. This strategy has now been used by several other labs, with a variety of genes and on different neurons (Harris et al. 2009; Yamada et al. 2009; Jose et al. 2009; Ezak et al. 2010). To optimize the efficiency of this approach we have tested the influence of genetic backgrounds that affect RNA interference. We show that in a rrf-3(pk1426) background silencing is more efficient. Although this result indicates the involvement of RNAi pathways in the silencing mechanism we have shown that there is no spreading of the silencing effect at least among amphidial chemosensory neurons and within the motorneurons of the ventral cord. We are now targeting chemosensory and mechanosensory neurons and two classes of motorneurons (GABAergic and HSN) using a variety of different promoters. We are testing the effect of silencing several essential genes on the development, morphology and survival of these neurons as well as on the behavior that they control.

Shu Liu et al. (2008) European Worm Meeting "Towards the search for a thermonociceptor"

Shu Liu, Maren Hertweck, Ralf Baumeister

[European Worm Meeting, 2008]

Upon exposure to noxious temperature, Caenorhabditis elegans executes an. escape reflex (Tav response) similar to the response to body touch. We had. previously shown that sensory neurons in the head and tail, but not in the. midbody region, are involved in the preception of heat. In vertebrates, the. capsaicin-sensitive vanilloid receptor VR1 of the TRP family has been shown. to be involved in the perception to heat, capsaicin, and low pH, and. several attempts have been made in other labs to relate TRP channels to the. sensation of external stimuli. We have begun a systematic phenotypic. analysis of available TRP channel mutants. Of 11 TRP mutants tested, only. osm-9 ocr-2 double mutants exhibited a severe Tav response defect. OSM-9. and OCR-2 have previously been demonstrated to function coordinately in C.. elegans olfaction and nose-touch responses (Tobin et al., 2002), and our. data support a similar model of coordinated sensory transduction in. thermonociception. OCR-2 and OSM-9 expression overlaps only in a few head. and tail neurons (Jose et al., 2007), suggesting that these could in. principle include candidates for thermonociceptors. We next tested a. variety of mutants whose genes have been reported to be expressed in. subsets of these neurons. sem-4 and unc-86 indeed displayed a reduced Tav. response in the tail, similar to the osm-9 ocr-2 double mutants'' defect. In. addition, one receptor mutant expressed in several classes of head neurons. also resulted in a mild yet significant anterior Tav defect, similar to. that seen in eat-4 and osm-9ocr-2 (79% Tav response). Taken together, we. are narrowing down our search for (a) sensory neuron(s) involved in the. perception of thermonoxious stimuli. We plan to carry out neuron ablations. to verify our findings.

Quartey MO et al. (2021) Sci Rep "The A(1-38) peptide is a negative regulator of the A(1-42) peptide implicated in Alzheimer disease progression."

Pennington PR, Heistad RM, Nyarko JNK, Barnes JR, Bolanos MAC, Parsons MP, Knudsen KJ, De Carvalho CE, Leary SC, Mousseau DD, Buttigieg J, Maley JM, Quartey MO

[Sci Rep, 2021]

The pool of -Amyloid (A) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for A peptides. We examined how a naturally occurring variant, e.g. A(1-38), interacts with the AD-related variant, A(1-42), and the predominant physiological variant, A(1-40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that A(1-38) interacts differently with A(1-40) and A(1-42) and, in general, A(1-38) interferes with the conversion of A(1-42) to a -sheet-rich aggregate. Functionally, A(1-38) reverses the negative impact of A(1-42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an A(1-42) phenotype in Caenorhabditis elegans. A(1-38) also reverses any loss of MTT conversion induced by A(1-40) and A(1-42) in HT-22 hippocampal neurons and APOE 4-positive human fibroblasts, although the combination of A(1-38) and A(1-42) inhibits MTT conversion in APOE 4-negative fibroblasts. A greater ratio of soluble A(1-42)/A(1-38) [and A(1-42)/A(1-40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that A(1-38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant A(1-42).

Danielle Thierry-Mieg et al. (2003) Worm Breeder's Gazette "www.wormgenes.org , a new gene centered database"

Vahan Simonyan, Michel Potdevin, Mark Sienkiewicz, Yuji KOHARA, Jean Thierry-Mieg, Danielle Thierry-Mieg, Tadasu SHIN-I

[Worm Breeder's Gazette, 2003]

Wormgenes is a new resource for C.elegans offering a detailed summary about each gene and a powerful query system.

Sean M O'Rourke et al. (2003) International Worm Meeting "Exploring the centrosome with proteomics and functional genomics."

Sean M O'Rourke, Bruce Bowerman

[International Worm Meeting, 2003]

The centrosome is a large eukaryotic organelle that organizes microtubules for cellular functions including setting up the mitotic spindle. Despite the important role of the centrosome, relatively little is known about its composition and regulatory mechanisms in metazoans. SPD-5 is a component of C. elegans centrosomes and contains multiple coiled-coil domains that may interact with other proteins thereby governing centrosomal structure (1). Because SPD-5 is thought to be a central component of centrosomes, it represents an excellent handle to pursue other genes and proteins that are also involved in centrosome function. We are taking two experimental routes to uncover additional centrosomal components and regulators.First, SPD-5 antibodies are being used to isolate protein complexes from embryonic extracts with the goal of purifying SPD-5-interacting proteins. Such proteins will be identified by mass spectrometry. To date, we have prepared embryonic extracts from N2 animals and we have successfully immunoprecipitated SPD-5 protein. Interestingly, two SPD-5 isoforms are apparent in our extracts, the significance of which remains to be determined. We are currently optimizing the purification procedure to obtain larger quantities of SPD-5 and interacting proteins. The interacting proteins we identify will be initially characterized by localization and RNAi inhibition studies.In the second route to understanding centrosome function, we are employing genome interaction screens to identify genes which, when knocked-down by feeding RNAi, alter the phenotypes of temperature-sensitive mutants. Building on the work of Jose Eduardo Gomes (see Gomes and Bowerman abstract), we have begun to use multiple-well plates for culturing worms and a robot to easily and accurately dispense the dsRNA-producing E. coli. We have performed a pilot semi-automated screen using the chromosome I library (2). Current results will be presented. In addition to examining spd-5, we are planning to perform genome-wide interaction RNAi feeding screens with 20 different temperature-sensitive mutants defective in several different processes. We envision generating a genetic interaction map that will be useful for determining how many different processes require any given gene. We anticipate that our use of many different sensitized genetic backgrounds will enable us to identify gene requirements missed in previous classical and genomic screens.(1) Hamill, D. R. et al. Developmental Cell 3, 673-684 (2002).(2) Fraser, A. G. et al. Nature 408, 325-330 (2000).

Tangrodchanapong T et al. (2020) Front Pharmacol "Frondoside A Attenuates Amyloid- Proteotoxicity in Transgenic Caenorhabditis elegans by Suppressing Its Formation."

Tangrodchanapong T, Sobhon P, Meemon K

[Front Pharmacol, 2020]

Oligomeric assembly of Amyloid- (A) is the main toxic species that contribute to early cognitive impairment in Alzheimer's patients. Therefore, drugs that reduce the formation of A oligomers could halt the disease progression. In this study, by using transgenic <i>Caenorhabditis elegans</i> model of Alzheimer's disease, we investigated the effects of frondoside A, a well-known sea cucumber <i>Cucumaria frondosa</i> saponin with anti-cancer activity, on A aggregation and proteotoxicity. The results showed that frondoside A at a low concentration of 1 M significantly delayed the worm paralysis caused by A aggregation as compared with control group. In addition, the number of A plaque deposits in transgenic worm tissues was significantly decreased. Frondoside A was more effective in these activities than ginsenoside-Rg3, a comparable ginseng saponin. Immunoblot analysis revealed that the level of small oligomers as well as various high molecular weights of A species in the transgenic <i>C. elegans</i> were significantly reduced upon treatment with frondoside A, whereas the level of A monomers was not altered. This suggested that frondoside A may primarily reduce the level of small oligomeric forms, the most toxic species of A. Frondoside A also protected the worms from oxidative stress and rescued chemotaxis dysfunction in a transgenic strain whose neurons express A. Taken together, these data suggested that low dose of frondoside A could protect against A-induced toxicity by primarily suppressing the formation of A oligomers. Thus, the molecular mechanism of how frondoside A exerts its anti-A aggregation should be studied and elucidated in the future.

Hodgkin JA (1998) International Journal of Developmental Biology "Seven types of pleiotropy."

Hodgkin JA

[International Journal of Developmental Biology, 1998]

Pleiotropy , a situation in which a single gene influences multiple phenotypic tra its, can arise in a variety of ways. This paper discusses possible underlying mechanisms and proposes a classification of the various phenomena involved.

Tuck S (2011) Curr Biol "Extracellular vesicles: budding regulated by a phosphatidylethanolamine translocase."

Tuck S

[Curr Biol, 2011]

Recent work on a Caenorhabditis elegans transmembrane ATPase reveals a central role for the aminophospholipid phosphatidylethanolamine in the production of a class of extracellular vesicles.

Viney ME et al. (2004) Naturwissenschaften "Is dauer pheromone of Caenorhabditis elegans really a pheromone?"

Viney ME, Franks NR

[Naturwissenschaften, 2004]

Animals respond to signals and cues in their environment. The difference between a signal (e.g. a pheromone) and a cue (e.g. a waste product) is that the information content of a signal is subject to natural selection, whereas that of a cue is not. The model free-living nematode Caenorhabditis elegans forms an alternative developmental morph (the dauer larva) in response to a so-called 'dauer pheromone', produced by all worms. We suggest that the production of 'dauer pheromone' has no fitness advantage for an individual worm and therefore we propose that 'dauer pheromone' is not a signal, but a cue. Thus, it should not be called a pheromone.