Asbestos body formation and iron accumulation in mouse peritoneal granulomas after the introduction of crocidolite asbestos fibers

Our plain-English summary of Asbestos body formation and iron accumulation in mouse peritoneal granulomas after the introduction of crocidolite asbestos fibers, by H.K. Koerten, J. Hazekamp, M. Kroon, et al (The American Journal of Pathology, 1990).

The study

• Authors: H.K. Koerten, J. Hazekamp, M. Kroon, W.T. Daems
• Journal: The American Journal of Pathology
• Published: 1990;136(1):141-57
• Cited by: 29 articles, as counted by NIH iCite
• Read it: PubMed · Free full text

Abstract

This report describes the cell biology of the development of asbestos bodies after a single intraperitoneal injection of a suspension of crocidolite asbestos fibers into the mouse peritoneal cavity. The majority of the infected fibers were found in aggregates of peritoneal macrophages, exudate cells, and fibrous tissue. These aggregates developed into granulomas containing not only numerous asbestos fibers, but also cells of various types, including macrophages, multinucleated giant cells, fibroblasts, plasma cells, granulocytes, and mast cells. Cytoplasmic ferritin was abundantly present in macrophages and giant cells. In addition, iron-rich inclusion bodies were detected. The results of this study show that asbestos body formation can occur outside the pleural cavity. Asbestos body formation occurred in the granulomas after periods of 1 month and longer. On the basis of morphologic criteria, various types of asbestos body were distinguished. X-ray microanalysis showed that variations in the density of the coat could attributed to the presence of chemical elements in various concentrations. Evidence is presented that asbestos body formation is an extracellular phenomenon.

In plain English

In this animal experiment, male Swiss mice received a single injection of crocidolite asbestos (1 ml of a 0.5 mg/ml suspension) into the abdominal (peritoneal) cavity. Control mice received the salt solution alone. The article does not state how many mice were used. Cells and tissue were examined by electron microscopy from 4 hours to 8 months later. Fibers and cells clumped together, were covered by the cavity's lining cells by 2 weeks, and from 1 month became granulomas (nodules of inflammatory tissue). Macrophages and giant cells in them contained iron-rich bodies. Asbestos bodies (fibers coated with an iron-rich layer) appeared from 1 month on. They were sorted into several types by their coats, some of which also contained calcium and phosphorus. Coats were never seen on fibers shorter than 10 micrometers. The authors concluded that asbestos body formation happens outside cells and can occur outside the lungs and pleural cavity. They also concluded that the mouse peritoneal cavity can serve as a model for studying it.

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: Animal experiment using electron microscopy and X-ray microanalysis of cells and granulomas at set times after a single injection
• Who was studied: Specific pathogen-free male Swiss mice, 8 weeks old and weighing 20 g, from the Central Institute for the Breeding of Laboratory Animals TNO, Zeist, The Netherlands. The number of mice is not stated. Control animals received salt solution without asbestos.
• Exposure: Crocidolite asbestos suspended in Hanks' balanced salt solution at 0.5 mg/ml; 1 ml injected once into the peritoneal cavity on day 0
• Main results:
  • At 8 months, the average peritoneal cell count in the crocidolite group was 16.4 million (plus or minus 2.1 million), compared with 5.3 million (plus or minus 0.2 million) in the control animals
  • In treated mice, aggregates of fibers and cells were covered by mesothelial cells by 2 weeks and became vascularized granulomas starting at 1 month
  • In the granulomas, cell death caused by the asbestos fibers was not observed
  • Macrophages and giant cells in the granulomas contained cytoplasmic ferritin and two types of iron-containing inclusion bodies
  • Asbestos bodies were seen in granulomas from 1 month onward. In cross-section their diameter ranged from 0.5 to 15 micrometers, mostly 5 to 10.
  • Several types of asbestos body were distinguished by coat structure and chemistry, ranging from iron-rich coats to coats with calcium and phosphorus
  • Among fibers extracted from granulomas, 0.1% to 1% were sometimes fully coated and a larger percentage partially coated. Asbestos bodies were never seen on fibers shorter than 10 micrometers.
  • The membrane around asbestos bodies was continuous with the cell's outer membrane, and free asbestos bodies were never found
• The authors' conclusion: The authors concluded that asbestos body formation is an extracellular phenomenon that can occur outside the lungs and pleural cavity, for example in the mouse peritoneal cavity. They also concluded that the mouse peritoneal cavity can serve as a model for studying asbestos body formation.
• Limitations the authors state:
  • The study found no indications of the source of the iron in the macrophages and asbestos bodies
  • The findings do not show whether repeated phagocytosis of asbestos bodies happens in living animals
  • The authors state that their results do not provide unequivocal proof that macrophages deposit calcium in the coats

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Body Formation, Granuloma, Crocidolite, Asbestos Bodies, Peritoneal Cavity, Macrophage, Exudate, Fibroblast.

Related studies

• In vivo accumulation of iron on crocidolite is associated with decrements in oxidant generation by the fiber — A.J. Ghio, A. LeFurgey, et al. (1997)
• The formation of asbestos bodies by mouse peritoneal macrophages. An in vitro study — H.K. Koerten, J.D. de Bruijn, et al. (1990)
• Tissue response to intraperitoneal asbestos with preliminary report of acute toxicity of heart-treated asbestos in mice — J. Jagatic, M.E. Rubnitz, et al. (1967)
• Iron mobilization from crocidolite asbestos greatly enhances crocidolite-dependent formation of DNA single-strand breaks in phi X174 RFI DNA — L.G. Lund, A.E. Aust (1992)
• Iron-dependent formation of 8-hydroxydeoxyguanosine in isolated DNA and mutagenicity in Salmonella typhimurium TA102 induced by crocidolite — S.P. Faux, P.J. Howden, et al. (1994)
• Synchrotron X-ray microscopy reveals early calcium and iron interaction with crocidolite fibers in the lung of exposed mice — L. Pascolo, G. Zabucchi, et al. (2016)

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