Anthelmintic drug actions in resistant and susceptible C. elegans revealed by electrophysiological recordings in a multichannel microfluidic device

Weeks, Janis C.; Robinson, Kristin J.; Lockery, Shawn R.; Roberts, William M.

doi:10.1016/j.ijpddr.2018.10.003

Cited by 26 publications

(45 citation statements)

References 112 publications

(208 reference statements)

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“…indicates that higher intestinal exposure increases the overall dose of IVM. Although the uptake capacities cannot be directly quantified, elegans bus-8 loss-of-function strain (53). In line with the findings of this study, a study by O'Lone and Campbell indicated that PP inhibition by refrigeration and thus inhibition of oral ingestion reduced the susceptibility to IVM in C. elegans (54).…”

Section: Discussionsupporting

confidence: 80%

Pharyngeal pumping and tissue-specific transgenic P-glycoprotein expression influence macrocyclic lactone susceptibility inCaenorhabditis elegans

Gerhard

Krücken

Neveu

et al. 2020

Preprint

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Macrocyclic lactone (ML) resistance has emerged in many parasitic nematodes including the pathogenic horse roundworm Parascaris univalens. The underlying mechanism of ML resistance and the drug penetration routes into the nematodes remain to be elucidated. Drug efflux by P-glycoproteins is considered a potential resistance mechanism but conclusive functional evidence is lacking. To this end, we used a motility assay modified to stimulate pharyngeal pumping (PP) by bacteria or serotonin and tissue-specific expression of Pun- PGP-9 in the free-living model nematode Caenorhabditis elegans. Here, stimulation of PP was identified as an important factor for C. elegans ML susceptibility, increasing the EC50 values of ivermectin by up to 11.1-fold and of moxidectin by 1.2-fold. In this context, intestinal Pun-PGP-9 expression elicited a protective effect against ivermectin and moxidectin only in the presence of PP stimulation, increasing the EC50 values by approximately 3- to 4-fold (ivermectin) or by < 1.3-fold (moxidectin). Conversely, epidermal Pun-PGP-9 expression protected against moxidectin regardless of PP with EC50 fold changes below 1.5 but against ivermectin with a considerable 2.9-fold EC50 increase only when the drug is not actively ingested. Our results highlight the role of active drug ingestion by nematodes for susceptibility and provide conclusive functional evidence for a contribution of P-glycoproteins to ML resistance.Author SummaryParasitic nematode infections pose a serious threat to animal health, in particular in light of the widespread anthelmintic resistance in different nematode species. In equines, the roundworm Parascaris univalens is a major pathogen of foals, exhibiting widespread resistance against macrocyclic lactones (MLs). This represents a particular challenge to animal health, but the underlying mechanisms and drug penetration routes remain mostly unknown. P-glycoprotein ABC-transporters have been linked to ML resistance in several parasitic nematodes. Here we demonstrate by tissue-specific overexpression of Pun-PGP-9 in the free-living model nematode Caenorhabditis elegans their ability to reduce the susceptibility to two commonly used MLs, ivermectin and moxidectin. At the same time, active drug ingestion by pharyngeal pumping (PP) strongly enhanced ivermectin and moderately effects moxidectin susceptibility. In more detail, the effect of intestinal or epidermal Pun-PGP-9 was dependent on active drug ingestion. These observations indicate differences in the drug penetration routes between ML derivatives and allow novel insight into the functional role of P-glycoproteins.

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Section: Discussionsupporting

confidence: 80%

Pharyngeal pumping and tissue-specific transgenic P-glycoprotein expression influence macrocyclic lactone susceptibility inCaenorhabditis elegans

Gerhard

Krücken

Neveu

et al. 2020

Preprint

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“…Many screens (although not all ( Weeks et al, 2018 )) to identify anthelmintic products rely on whole-worm motility assays to assess efficacy. While important, immotility is a non-specific outcome that may result from many different causes.…”

Section: Introductionmentioning

confidence: 99%

Rapid determination of nematode cell and organ susceptibility to toxic treatments

Jasmer

Rosa

Tyagi

et al. 2020

International Journal for Parasitology: Drugs and Drug Resistan

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In research focused on the intestine of parasitic nematodes, we recently identified small molecule inhibitors toxic to intestinal cells of larval Ascaris suum (nematode intestinal toxins/toxicants; “NITs”). Some NITs had anthelmintic activity across the phylogenetic diversity of the Nematoda. The whole-worm motility inhibition assay quantified anthelmintic activity, but worm responses to NITs in relation to pathology or affected molecular pathways was not acquired. In this study we extended this research to more comprehensively determine in whole larval A. suum the cells, organ systems, molecular targets, and potential cellular pathways involved in mechanisms of toxicity leading to cell death. The experimental system utilized fluorescent nuclear probes (bisbenzimide, propidium iodide), NITs, an A. suum larval parasite culture system and transcriptional responses (RNA-seq) to NITs. The approach provides for rapid resolution of NIT-induced cell death among organ systems (e.g. intestine, excretory, esophagus, hypodermis and seam cells, and nervous), discriminates among NITs based on cell death profiles, and identifies cells and organ systems with the greatest NIT sensitivity (e.g. intestine and apparent neuronal cells adjacent to the nerve ring). Application was extended to identify cells and organs sensitive to several existing anthelmintics. This approach also resolved intestinal cell death and irreparable damage induced in adult A. suum by two NITs, establishing a new model to elucidate relevant pathologic mechanisms in adult worms. RNA-seq analysis resolved A. suum genes responsive to treatments with three NITs, identifying dihydroorotate dehydrogenase (uridine synthesis) and RAB GTPase(s) (vesicle transport) as potential targets/pathways leading to cell death. A set of genes induced by all three NITs tested suggest common stress or survival responses activated by NITs. Beyond the presented specific lines of research, elements of the overall experimental system presented in this study have broad application toward systematic development of new anthelmintics.

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“…For IVM and a few other anthelmintics, transcuticular-epidermal permeability had already been described by biophysical studies on cuticle–epidermis preparations of Ascaris suum and experiments using live A. suum with a surgically ligated pharynx [ 49 , 50 ]. Likewise, experiments in C. elegans have demonstrated a considerably quicker onset of pharyngeal paralysis in a cuticle defective C. elegans bus-8 loss-of-function strain [ 51 ]. A study by O’Lone and Campbell indicated that PP inhibition by refrigeration, and thus inhibition of oral ingestion, reduced the susceptibility to IVM in C. elegans [ 52 ].…”

Section: Discussionmentioning

confidence: 99%

Pharyngeal Pumping and Tissue-Specific Transgenic P-Glycoprotein Expression Influence Macrocyclic Lactone Susceptibility in Caenorhabditis elegans

et al. 2021

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Macrocyclic lactones (MLs) are widely used drugs to treat and prevent parasitic nematode infections. In many nematode species including a major pathogen of foals, Parascaris univalens, resistance against MLs is widespread, but the underlying resistance mechanisms and ML penetration routes into nematodes remain unknown. Here, we examined how the P-glycoprotein efflux pumps, candidate genes for ML resistance, can modulate drug susceptibility and investigated the role of active drug ingestion for ML susceptibility in the model nematode Caenorhabditis elegans. Wildtype or transgenic worms, modified to overexpress P. univalens PGP-9 (Pun-PGP-9) at the intestine or epidermis, were incubated with ivermectin or moxidectin in the presence (bacteria or serotonin) or absence (no specific stimulus) of pharyngeal pumping (PP). Active drug ingestion by PP was identified as an important factor for ivermectin susceptibility, while moxidectin susceptibility was only moderately affected. Intestinal Pun-PGP-9 expression elicited a protective effect against ivermectin and moxidectin only in the presence of PP stimulation. Conversely, epidermal Pun-PGP-9 expression protected against moxidectin regardless of PP and against ivermectin only in the absence of active drug ingestion. Our results demonstrate the role of active drug ingestion by nematodes for susceptibility and provide functional evidence for the contribution of P-glycoproteins to ML resistance in a tissue-specific manner.

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Anthelmintic drug actions in resistant and susceptible C. elegans revealed by electrophysiological recordings in a multichannel microfluidic device

Cited by 26 publications

References 112 publications

Pharyngeal pumping and tissue-specific transgenic P-glycoprotein expression influence macrocyclic lactone susceptibility inCaenorhabditis elegans

Pharyngeal pumping and tissue-specific transgenic P-glycoprotein expression influence macrocyclic lactone susceptibility inCaenorhabditis elegans

Rapid determination of nematode cell and organ susceptibility to toxic treatments

Pharyngeal Pumping and Tissue-Specific Transgenic P-Glycoprotein Expression Influence Macrocyclic Lactone Susceptibility in Caenorhabditis elegans

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