Differential Effects in Mammalian Cells Induced by Chemical Mixtures in Environmental Biota As Profiled Using Infrared Spectroscopy

Abstract

Environmental contaminants accumulate in many organisms and induce a number of adverse effects. As contaminants mostly occur in the environment as mixtures, it remains to be fully understood which chemical interactions induce the most important toxic responses. In this study, we set out to determine the effects of chemical contaminants extracted from Northern Gannet (Morus bassanus) eggs (collected from the UK coast from three sampling years (1987, 1990, and 1992) on cell cultures using infrared (IR) spectroscopy with computational data handling approaches. Gannet extracts were chemically analyzed for different contaminants, and MCF-7 cell lines were treated for 24 h in a dose-related manner with individual-year extracts varying in their polybrominated diphenyl ether (PBDE) to polychlorinated biphenyl (PCB) ratios. Treated cellular material was then fixed and interrogated using attenuated total reflection Fourier-transform IR (ATR-FTIR) spectroscopy; resultant IR spectra were computationally analyzed to derive dose-response relationships and to identify biomarkers associated with each contaminant mixture treatment. The results show distinct biomarkers of effect are related to each contamination scenario, with an inverse relationship with dose observed. This study suggests that specific contaminant mixtures induce cellular alterations in the DNA/RNA spectral region that are most pronounced at low doses. It also suggests alterations in the "biochemical-cell fingerprint" of IR spectra can be indicative of mixture exposures.

Using Fourier transform IR spectroscopy to analyze biological materials

“…The use of a single-element detector allows for individual point spectra to be obtained across a whole sample (for instance, useful when analyzing biofluids); a particular application has been to derive single-cell–specific fingerprint spectra across a heterogeneous tissue section. Acquiring large data sets containing point spectra is a method regularly used in biomedical and environmental studies coupled with multivariate data analysis 40,73 . Although time consuming, point spectra often have a high SNR, resulting in high-quality spectra, as spatial resolution is limited by IR apertures 74 .…”

Real-world carbon nanoparticle exposures induce brain and gonadal alterations in zebrafish (Danio rerio) as determined by biospectroscopy techniques

“…Infrared (IR) spectroscopy, including attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy, has been applied in disease diagnosis 19 and toxic assessment of environmental contamination within cells. 20,21 In ATR-FTIR instrumentation, a mid-IR beam (λ = 2-20 µm) is transmitted through an internal reflection element (e.g., diamond, zinc selenide, germanium, silicon) in contact with the samples and penetrates a small distance beyond the sample surface, allowing the generation of bio-chemical fingerprint spectra (1800-900 cm −1 ). Raman spectroscopy is a complimentary spectral method, which can also detect a wide range of chemical bonds in cells and tissues.…”

Diet-sourced carbon-based nanoparticles induce lipid alterations in tissues of zebrafish (Danio rerio) with genomic hypermethylation changes in brain

“…We then examined the lipidomic profile of exposed vs. control in brain, gonads and gastrointestinal tissues. Whilst the liver acts as a portal to the body in many sentinel organisms (43), only in a small number of cases is it the target for consequent pathology. The tissues chosen in this study were chosen to determine whether CBNs possess potential to induce developmental alterations (i.e.…”