Glutathione S-transferases play a role in the detoxification of flumethrin and chlorpyrifos in Haemaphysalis longicornis

Abstract

BackgroundHaemaphysalis longicornis is a tick of importance to health, as it serves as a vector of several pathogens, including Theileria orientalis, Babesia ovata, Rickettsia japonica and the severe fever with thrombocytopenia syndrome virus (SFTSV). Presently, the major method of control for this tick is the use of chemical acaricides. The glutathione S-transferase (GST) system is one mechanism through which the tick metabolizes these acaricides. Two GSTs from H. longicornis (HlGST and HlGST2) have been previously identified.ResultsEnzyme kinetic studies were performed to determine the interaction of acaricides with recombinant H. longicornis GSTs. Recombinant HlGST activity was inhibited by flumethrin and cypermethrin, while recombinant HlGST2 activity was inhibited by chlorpyrifos and cypermethrin. Using real-time RT-PCR, the upregulation of the HlGST gene was observed upon exposure to sublethal doses of flumethrin, while the HlGST2 gene was upregulated when exposed to sublethal doses of chlorpyrifos. Sex and strain dependencies in the induction of GST gene expression by flumethrin were also observed. Knockdown of the HlGST gene resulted in the increased susceptibility of larvae and adult male ticks to sublethal doses of flumethrin and the susceptibility of larvae against sublethal doses of chlorpyrifos was increased upon knockdown of HlGST2.ConclusionsHlGST could be vital for the metabolism of flumethrin in larvae and adult male ticks, while HlGST2 is important in the detoxification of chlorpyrifos in larval ticks.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-3044-9) contains supplementary material, which is available to authorized users.

Long‐ term effects of water quality on the freshwater bivalve Diplodon chilensis (Unionida: Hyriidae) caged at different sites in a North Patagonian river (Argentina)

“…GSH is a non-enzymatic antioxidant, which could be directly used to scavenge oxygen free radicals to protect the cells (Regoli & Principato, 1995), used as substrate by antioxidant enzymes or conjugated with various endogenous and exogenous substances in a biotransformation reaction catalysed by GST (Regoli, Nigro, & Orlando, 1998). This enzyme can be induced by organic compounds (Hernandez et al, 2018;Hoarau, Gnassia-Barelli, Romeo, & Girard, 2001) and different metals, such as copper (Canesi, Viarengo, Leonzio, Filippelli, & Gallo, 1999;Roméo et al, 2003;Sabatini, Rocchetta, Nahabedian, et al, 2011), manganese and zinc (Di Salvatore et al, 2013). GST not only detoxifies anthropogenic chemicals by biotransformation reactions but also plays an important role in the antioxidant defence (Awasthi, Ramanaa, Chaudhary, Srivastava, & Awasthi, 2017;Dasari, Ganjayi, Oruganti, Balaji, & Meriga, 2017).…”

Aryl hydrocarbon receptor regulates the expression of LmGSTd7 and is associated with chlorpyrifos susceptibility in Locusta migratoria

“…Our previous study suggested that increased GST activity was one of the mechanisms underlying chlorpyrifos resistance in L. migratoria . The silencing of HlGST2 resulted in increased mortality in Haemaphysalis longicornis larvae exposed to chlorpyrifos . Two epsilon GST genes ( BdGSTe2 and BdGSTe4 ) were significantly overexpressed in malathion‐resistant strains and played a key role in the generation of malathion resistance in Bactrocera dorsalis (Hendel) .…”

Gene Expression in the Salivary Gland of Rhipicephalus (Boophilus) microplus Fed on Tick-Susceptible and Tick-Resistant Hosts

“…GGT is an enzyme present in cell membranes and is involved in cross-cell-membrane trafficking of amino acids and peptides and in glutathione metabolism (Mulenga and Erikson, 2011). Glutathione S-transferases (GST) are proteins that belong to a multigene family and play a central role in the detoxification of xenobiotic compounds (de Lima et al, 2002), with increased expression levels being correlated with insecticide resistance in various organisms, including ticks (Nandi et al, 2015;Hernandez et al, 2018). GGT plays key roles in intracellular reduced glutathione (GSH) homeostasis by breaking down the extracellular molecule and providing cysteine for intracellular de novo synthesis of GSH (Accaoui et al, 2000;Zhang et al, 2005).…”

“…The authors also related that increased expression of GGT during oxidative stress facilitates GSH turnover, de novo GSH synthesis, and metabolism and detoxification of GSH conjugates, increasing cell resistance to subsequent stress. In Haemaphysalis longicornis, the analysis of two GSTs using realtime PCR showed that gene expression increases continuously in salivary glands and other organs of the tick as blood-feeding progresses until female engorgement, demonstrating the possible role of GSTs in coping with oxidative stress caused by bloodfeeding (Hernandez et al, 2018).…”

“…Gene transcripts, such as glutathione S-transferase and gamma-glutamyl transferase, can be found in salivary glands because they have physiological functions; one of these genes plays a central role in the detoxication of xenobiotic compounds (de Lima et al, 2002), such as insecticides (Nandi et al, 2015;Hernandez et al, 2018), and another of which is involved in the cross-cell membrane trafficking of amino acids and peptides and in glutathione metabolism, respectively (Mulenga and Erikson, 2011).…”