Cultured airway epithelium responses to mineral particles: role of the oxidative stress

Our plain-English summary of Cultured airway epithelium responses to mineral particles: role of the oxidative stress, by C. Guilianelli, A. Baeza-Squiban, E. Lapart, et al (Toxicology Letters, 1996).

The study

• Authors: C. Guilianelli, A. Baeza-Squiban, E. Lapart, F. Marano
• Journal: Toxicology Letters
• Published: 1996;88(1-3):39-44
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We tested the hypothesis according to which mineral particles containing iron would be able to produce cytotoxic-ROS. We approached this problem in vitro using primary cultures of rabbit tracheal epithelial cells. The oxidizing power of three mineral particles, i.e. nemalite, chrysotile and hematite, has been evaluated for their capacity to induce lipid peroxidation, and to activate intra-cellular anti-oxidant enzymes. The results show that nemalite and chrysotile which contain Fe2+ have a strong oxidizing power, inducing an oxidative stress on airway epithelial cells, whereas hematite, the Fe3+ containing particles, is without effect.

In plain English

This was a laboratory experiment using primary cultures of rabbit tracheal epithelial cells grown from tracheal explants. The authors tested whether iron-containing mineral particles induce oxidative stress, comparing chrysotile B (contaminated by nemalite 5% and magnetite), nemalite (a fibrous brucite in which about 8% of the Mg2+ are substituted by Fe2+) and hematite (containing Fe3+). Lipid peroxidation was measured as malondialdehyde (MDA) by the thiobarbituric acid assay after 1 h of treatment at 100 micrograms per cm2, and catalase and superoxide dismutase (SOD) activities after 24 h at 10 micrograms per cm2. Chrysotile and nemalite significantly induced lipid peroxidation, chrysotile being more active than nemalite, while hematite had no effect compared with control. Chrysotile gave the strongest induction of catalase and SOD; nemalite significantly induced SOD but not catalase, with a dose-response for SOD; hematite showed no significant effect. Catalase or SOD added to the medium gave no protection against lipid peroxidation. The authors concluded that Fe2+-containing particles produce reactive oxygen species and induce oxidative stress in airway epithelial cells.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: in vitro cell culture experiment on primary rabbit tracheal epithelial cells exposed to mineral particles
• Who was studied: Primary cultures of rabbit tracheal epithelial (RTE) cells obtained by the explant technique from Fauve de Bourgogne rabbits; cultures treated at 7-8 days, with 4 to 6 individual cultures per experiment
• Exposure: Three mineral particles differing in iron content: chrysotile B (contaminated by nemalite 5% and magnetite), nemalite (fibrous brucite, about 8% of Mg2+ substituted by Fe2+) and hematite (Fe3+); 100 micrograms per cm2 for 1 h for lipid peroxidation and 10 micrograms per cm2 for 24 h for enzyme activities
• Main results:
  • Chrysotile and nemalite significantly induced lipid peroxidation within 1 h at 100 micrograms per cm2; chrysotile was more active than nemalite, and hematite had no effect compared with control cultures (P less than 0.05)
  • Catalase (1400 U/ml) or SOD (400 U/ml) added to the medium together with nemalite or chrysotile gave no protection against the lipid peroxidation
  • After 24 h at 10 micrograms per cm2, chrysotile gave the strongest induction of catalase and SOD activities; nemalite significantly induced SOD but not catalase
  • SOD activity induction rose with increasing nemalite dose
  • Hematite showed no significant effect on catalase or SOD activity
• The authors' conclusion: The authors concluded that Fe2+-containing mineral particles such as chrysotile and nemalite produce reactive oxygen species and thereby induce an oxidative stress in airway epithelial cells, whereas the Fe3+-containing hematite does not
• Limitations the authors state:
  • The authors stated that the exact nature of the reactive oxygen species produced by the particles could not be definitely determined from their ESR measurements
  • Some comparative data (treatment with H2O2 associated with iron) were not shown in the paper

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

Medical terms in this study, explained in our Lexicon: Epithelium, Oxidative Stress, Chrysotile, Hematite.

Related studies

• Effect of mineral particles containing iron on primary cultures of rabbit tracheal epithelial cells: possible implication of oxidative stress — C. Guilianelli, A. Baeza-Squiban, et al. (1993)
• Microsomal lipid peroxidation and oxy-radicals formation are induced by insoluble iron-containing minerals — M. Fontecave, M. Jaouen, et al. (1990)
• Augmentation of chrysotile-induced oxidative stress by BHA in mice lungs — I. Ahmad, K. Krishnamurthi, et al. (1995)
• Iron enhances uptake of mineral particles and increases lipid peroxidation in tracheal epithelial cells — B. Keeling, K.Y. Li, et al. (1994)
• Mechanisms of oxidative stress and alterations in gene expression by Libby six-mix in human mesothelial cells — J.M. Hillegass, A. Shukla, et al. (2010)
• Dispersion medium modulates oxidative stress response of human lung epithelial cells upon exposure to carbon nanomaterial samples — E. Herzog, H.J. Byrne, et al. (2009)

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