Nickel-induced cell death and survival pathways in cultured renal proximal tubule cells: roles of reactive oxygen species, ceramide and ABCB1.
Nickel and nickel compounds are carcinogens that target the lungs and kidneys causing cell death or cell survival adaptation. The multidrug resistance P-glycoprotein ABCB1 protects cells against toxic metabolites and xenobiotics and is upregulated in many cancer cell types. Here, we investigated the role of ABCB1 in nickel-induced stress signaling mediated by reactive oxygen species (ROS) and ceramides. In renal proximal tubule cells, nickel chloride (0.1-0.25 mM) increased both ROS formation, detected by 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate, and cellular ceramides, which were determined by lipid dot blot and surface immunostaining, culminating in decreased cell viability, increased DNA fragmentation, augmented PARP-1 cleavage, and increased ABCB1 mRNA and protein. Inhibitors of the de novo ceramide synthesis pathway (fumonisin B1, L-cycloserine) and an antioxidant (α-tocopherol) attenuated nickel-induced toxicity as well as induction of ABCB1. ABCB1 protects against nickel toxicity as PSC833, an ABCB1 blocker, augmented the decrease in cell viability by nickel. Moreover, nickel toxicity was attenuated in renal MDCK cells stably overexpressing ABCB1. In agreement with previous data that demonstrated extrusion of (glucosyl)ceramides by ABCB1 (Lee et al. in Toxicol Sci 121:343, 2011), PSC833 increased total cellular ceramides by >2-fold after nickel treatment. Further, glucosylceramide synthase (GCS) mRNA is upregulated by nickel at 3 h by ~1.5-fold but declined with prolonged exposures (6-24 h). Inhibition of GCS with C9DGJ or knockdown of GCS with siRNA significantly attenuated nickel toxicity. In conclusion, nickel induces a ROS-ceramide pathway to cause apoptotic cell death as well as activate adaptive survival responses, including upregulation of ABCB1, which improves cell survival by extruding proapoptotic (glucosyl)ceramides.
Institute for Physiology, Pathophysiology and Toxicology, Centre for Biomedical Research and Training (ZBAF), Faculty of Health, University of Witten/Herdecke, Stockumer Str. 12, 58453, Witten, Germany.
Faouzi
F
Dahdouh
Maximilian
M
Raane
Frank
F
Thévenod
Wing-Kee
WK
Lee
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005963:Glucosylceramides / Q000378:metabolism*; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D061985:Madin Darby Canine Kidney Cells; D009532:Nickel / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation
C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D004791:Enzyme Inhibitors; D005963:Glucosylceramides; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C022838:nickel chloride; D009532:Nickel; C095122:multidrug resistance protein 3; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase