title: Earthworms and humans in vitro: characterizing evolutionarily conserved stress and immune responses to silver nanoparticles.
abstract: Little is known about the potential threats of silver nanoparticles (AgNPs) to ecosystem health, with no detailed report existing on the stress and immune responses of soil invertebrates. Here we use earthworm primary cells, cross-referencing to human cell cultures with a particular emphasis on the conserved biological processes, and provide the first in vitro analysis of molecular and cellular toxicity mechanisms in the earthworm Eisenia fetida exposed to AgNPs (83 ± 22 nm). While we observed a clear difference in cytotoxicity of dissolved silver salt on earthworm coelomocytes and human cells (THP-1 cells, differentiated THP-1 cells and peripheral blood mononuclear cells), the coelomocytes and differentiated (macrophage-like) THP-1 cells showed a similar response to AgNPs. Intracellular accumulation of AgNPs in the coelomocytes, predominantly in a phagocytic population, was evident by several methods including transmission electron microscopy. Molecular signatures of oxidative stress and selected biomarker genes probed in a time-resolved manner suggest early regulation of oxidative stress genes and subsequent alteration of immune signaling processes following the onset of AgNP exposure in the coelomocytes and THP-1 cells. Our findings provide mechanistic clues on cellular innate immunity toward AgNPs that is likely to be evolutionarily conserved across the animal kingdom.
authors.affiliation: iNANO Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark. yuya@inano.au.dk
authors.forename: Yuya
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Péter
authors.initials: P
authors.lastname: Engelmann
authors.forename: Rasmus
authors.initials: R
authors.lastname: Foldbjerg
authors.forename: Mariann
authors.initials: M
authors.lastname: Szabó
authors.forename: Ildikó
authors.initials: I
authors.lastname: Somogyi
authors.forename: Edit
authors.initials: E
authors.lastname: Pollák
authors.forename: László
authors.initials: L
authors.lastname: Molnár
authors.forename: Herman
authors.initials: H
authors.lastname: Autrup
authors.forename: Duncan S
authors.initials: DS
authors.lastname: Sutherland
authors.forename: Janeck
authors.initials: J
authors.lastname: Scott-Fordsmand
authors.forename: Lars-Henrik
authors.initials: LH
authors.lastname: Heckmann
mesh_terms: D000818:Animals; D005075:Biological Evolution; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007109:Immunity / Q000187:drug effects* / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008297:Male; D053768:Metal Nanoparticles / Q000633:toxicity* / Q000648:ultrastructure; D009835:Oligochaeta / Q000187:drug effects* / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000633:toxicity*; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D013997:Time Factors
chemical_list: D017382:Reactive Oxygen Species; D012834:Silver