Transporter-interfering chemicals inhibit P-glycoprotein of yellowfin tuna (Thunnus albacares)

Abstract

Marine pollutants bioaccumulate at high trophic levels of marine food webs and are transferred to humans through consumption of apex species. Yellowfin tuna (Thunnus albacares) are marine predators, and one of largest commercial fisheries in the world. Previous studies have shown that yellowfin tuna can accumulate high levels of persistent organic pollutants, including Transporter Interfering Chemicals (TICs), which are chemicals shown to bind to mammalian xenobiotic transporters and interfere with their function. Here, we examined the extent to which these same compounds might interfere with the activity of the yellowfin tuna (Thunnus albacares) ortholog of this transporter. To accomplish this goal we identified, expressed, and functionally assayed tuna ABCB1. The results demonstrated a common mode of vertebrate ABCB1 interaction with TICs that predicts effects across these species, based on high conservation of specific interacting residues. Importantly several TICs showed potent inhibition of Ta-ABCB1, such as the organochlorine pesticides Endrin (EC 50 = 1.2 ± 0.2 μM) and Mirex (EC 50 = 2.3 ± 0.9 μM). However, unlike the effects observed on mouse ABCB1, low concentrations of the organochlorine pesticide TICs p,p'-DDT and its metabolite p,p'-DDD co-stimulated verapamil-induced Ta-ABCB1 ATPase activity possibly suggesting a low transport activity for these ligands in tuna. These results provide a mechanistic basis for understanding the potential vulnerability of tuna to these ubquitous pollutants.

Characterization and tissue localization of zebrafish homologs of the human ABCB1 multidrug transporter

“…For all proteins, verapamil significantly stimulated ATPase activity compared to basal levels ( p < 0.02). This is in agreement with a previous report in which verapamil-inducible ATPase activity was demonstrated for zebrafish Abcb4 15 as well as more recently for yellowfish tuna ABCB1 23 . Basal ATPase activity could be inhibited by the addition of 1 µM tariquidar (Fig.…”

Interactions of Environmental Chemicals and Natural Products With ABC and SLC Transporters in the Digestive System of Aquatic Organisms

“…Thereby, baseline levels of MXR inducibility and activity between different species have been correlated with the amount of pollution present in their habitat ( Kurelec et al, 1995 ; Smital et al, 2000 ). Over the past three decades, fish and other aquatic invertebrates, such as sea urchins and mussels, have been instrumental in understanding MXR transporter interactions with xenobiotics and the chemosensitization effects of so called Transporter-Interfering Chemicals or TICs ( Eufemia et al, 2002 ; Hamdoun et al, 2004 ; Luckenbach and Epel, 2005 , 2008 ; Kwong et al, 2006 ; Stevenson et al, 2006 ; Faria et al, 2011 ; Martins et al, 2020 ; Nicklisch and Hamdoun, 2020 ; Protopopova et al, 2020 ; Nicklisch et al, 2021 ).…”

“…The identification of two P-glycoprotein genes in the winter flounder Pleuronectes americanus using Southern blot techniques represented the first set of P-glycoprotein orthologs reported in lower vertebrates ( Chan et al, 1992 ; Luckenbach et al, 2014 ; Gordon et al, 2019 ). Since then, numerous ABC transporter proteins, which mediate the MXR phenotype, have been identified, characterized, and cloned in other fish species including Emerald rockcod ( Zucchi et al, 2010 ), carp ( Smital and Sauerborn, 2002 ), catfish ( Liu et al, 2013 ), killifish ( Christine Paetzold et al, 2009 ), mullet ( Diaz de Cerio et al, 2012 ), Nile tilapia ( Costa et al, 2012 , 2013 ), rainbow trout ( Lončar et al, 2010 ; Kropf et al, 2016 ; Love et al, 2021 ), zebrafish ( Popovic et al, 2010b ; Long et al, 2011 ; Fischer et al, 2013 ), and more recently yellowfin tuna ( Nicklisch et al, 2021 ).…”

“… Compounds marked with an asterisk (*) have been previously identified as Transporter-Interfering Chemicals or TICs ( Nicklisch et al, 2016 , 2021 ; Nicklisch and Hamdoun, 2020 ). T.a., Thunnus albacares; D.r., Danio rerio; O.m, Oncorhynchus mykiss; O.h., Odontesthes hatcheri; P.l., Poeciliopsis lucida; D.p., Dreissena polymorpha; M.c., Mytilus californianus; P.m., Psammechinus miliaris; S, substrate; I, inhibitor; WI, weak interactor (i.e., compounds that are not recognized or weakly interact with MXR transporters and do not alter transporter activity or function ( Nicklisch and Hamdoun, 2020 ); BTs, biotoxins; NEM-SG, N-ethylmaleimide S-glutathione; CDEC, chloroallyl diethyldithiocarbamate; AHTN, Acetyl-hexamethyltetrahydro-naphthalene; DCPA, Dimethyl tetrachloroterephthalate; MPP+, 1-methyl-4-phenylpyridinum; 2,4-D, 2,4-dichlorophenoxyacetic acid; DHEAS, dehydroepiandrosterone sulfate; PFDA, Perfluorodecanoic acid; PFHxS, Perfluorohexanesulfonate; PFNA, Perfluorononanoic acid; PFOS, Perfluorooctanesulfonic acid; PFOA, Perfluorooctanoic acid.…”

“…Many of the environmental chemicals that have been tested with MDR/MXR and nutrient uptake transporters were shown to be competitive substrates or inhibitors of the transporters in aquatic organisms. These so-called Transporter-Interfering Chemicals or TICs had been previously identified and shown to bind and inhibit mammalian and fish defense transporters, such as ABCB1 ( Nicklisch et al, 2016 , 2021 ; Nicklisch and Hamdoun, 2020 ). It has been hypothesized that the exact type of transporters also serve endogenous roles during development and for maintaining cellular and organismal homeostasis ( Ahn and Nigam, 2009 ; Wu et al, 2011 ; Nigam, 2015 , 2018 ).…”