title: Bimodal responses of cells to trace elements: insights into their mechanism of action using a biospectroscopy approach.
abstract: Understanding how organisms respond to trace elements is important because some are essential for normal bodily homeostasis, but can additionally be toxic at high concentrations. The inflection point for many of these elements is unknown and requires sensitive techniques capable of detecting subtle cellular changes as well as cytotoxic alterations. In this study, we treated human cells with arsenic (As), copper or selenium (Se) in a dose-response manner and used attenuated total reflection Fourier-transform infrared (ATR-FTIR) microspectroscopy combined with computational analysis to examine cellular alterations. Cell cultures were treated with As(V), Cu(2+) or Se(IV) at concentrations ranging from 0.001 mg L(-1) to 1000 mg L(-1) and their effects were spectrochemically determined. Results show that As(V) and Cu(2+) induce bimodal dose-response effects on cells; this is in line with hormesis-driven responses. Lipids and proteins seem to be the main cell targets for all the elements tested; however, each compound produced a unique fingerprint of effect. Spectral biomarkers indicate that all test agents generate reactive oxygen species (ROS), which could either stimulate repair mechanisms or induce damage in cells.
authors.affiliation: Centre for Biophotonics, Lancaster University, Lancaster LA1 4YQ, UK; Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK. Electronic address: v.llabjani@lancaster.ac.uk.
authors.forename: Valon
authors.initials: V
authors.lastname: Llabjani
authors.affiliation: Department of Mathematics and Statistics, Lancaster University, Lancaster LA1 4YF, UK.
authors.forename: Valmira
authors.initials: V
authors.lastname: Hoti
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Hamid M
authors.initials: HM
authors.lastname: Pouran
authors.affiliation: Centre for Biophotonics, Lancaster University, Lancaster LA1 4YQ, UK; Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Francis L
authors.initials: FL
authors.lastname: Martin
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001151:Arsenic / Q000494:pharmacology* / Q000633:toxicity*; D003300:Copper / Q000494:pharmacology* / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000494:pharmacology / Q000633:toxicity; D059165:Hormesis / Q000187:drug effects*; D006801:Humans; D061986:MCF-7 Cells; D015999:Multivariate Analysis; D012643:Selenium / Q000494:pharmacology* / Q000633:toxicity*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004785:Environmental Pollutants; D003300:Copper; D012643:Selenium; D001151:Arsenic
keywords: ATR-FTIR spectroscopy; Arsenic; Copper; Dose-response; Hormesis; Selenium