The selective release of lysosomal acid hydrolases from mouse peritoneal macrophages by stimuli of chronic inflammation

Our plain-English summary of The selective release of lysosomal acid hydrolases from mouse peritoneal macrophages by stimuli of chronic inflammation, by H.U. Schorlemmer, P. Davies, W. Hylton, et al (British Journal of Experimental Pathology, 1977).

The study

• Authors: H.U. Schorlemmer, P. Davies, W. Hylton, M. Gugig, A.C. Allison
• Journal: British Journal of Experimental Pathology
• Published: 1977;58(3):315-26
• Cited by: 92 articles, as counted by NIH iCite
• Read it: PubMed · Free full text

Abstract

The paralelism between the capacity of various agents to elicit chronic inflammatory responses in vivo and to induce the selective release of lysosomal enzymes from cultures of mouse peritoneal macrophages in vitro is discussed. Zymosan elicits an intense inflammatory response when injected i.m. in mice. Chrysotile asbestos produces a response of a similar nature and intensity as is seen with zymosan, while injections of acid-leached asbestos and polystyrene latex are not followed by inflammation. It is also shown that zymosan and asbestos induce a dose-dependent increase in the total enzyme activity of an inflamed muscle. On the other hand latex and acid-leached asbestos caused no significant increases in lysosomal enzyme levels. Agents eliciting inflammatory responses, such as zymosan and chrysotile asbestos induce a selective release of acid hydrolases from cultured macrophages; in contrast agents lacking the capacity to induce inflammation, such as latex and acid-leached chrysotile asbestos, do not induce the release of lysosomal enzymes from cultured macrophages.

In plain English

This laboratory study in mice compared chrysotile asbestos soaked in water with chrysotile soaked in hydrochloric acid. The acid removed about 92.8% of the fibers' magnesium; the water removed 0.53%. The authors injected these materials into the hamstring muscles of Swiss mice and examined the muscle 7 days later. As comparisons they also injected zymosan, a yeast product known to cause inflammation, and polystyrene latex beads. They also exposed cultured mouse peritoneal macrophages, immune cells taken from the abdominal cavity, to the same materials. Water-treated chrysotile caused muscle inflammation similar to zymosan's and a dose-related rise in lysosomal enzyme activity. Acid-leached chrysotile caused only a low-grade response and no significant enzyme rise. In culture, water-treated chrysotile raised the share of a lysosomal enzyme released into the medium from about 10% to nearly 50% at 50 micrograms per millilitre. Acid-leached chrysotile raised it only to 20%. Neither asbestos sample showed signs of killing the cells. The authors concluded that acid leaching greatly reduced chrysotile's ability to cause inflammation and enzyme release. They said the mechanism needed further study.

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 (intramuscular injection in mice) combined with in vitro experiments on cultured mouse macrophages
• Who was studied: Swiss mice (T.O. strain) from a UK supplier, and peritoneal macrophages collected from such mice and grown in culture (quadruplicate cultures); the number of mice is not stated
• Exposure: UICC standard reference Rhodesian chrysotile, either acid-leached (1M hydrochloric acid for 432 h, removing 92.8% of magnesium) or water-treated as a control (625 h, removing 0.53% of magnesium); compared with zymosan (inflammatory) and polystyrene latex (non-inflammatory). Muscle doses were 50-400 micrograms; culture concentrations of asbestos were up to 50 micrograms/ml.
• Main results:
  • In mouse muscle 7 days after injection, unleached (water-treated) chrysotile caused inflammation similar in nature and intensity to zymosan, while acid-leached chrysotile caused only a low-grade response with a few inflammatory cells
  • Water-treated chrysotile produced a dose-dependent increase in lysosomal enzyme content of the injected muscle
  • Acid-leached chrysotile did not significantly increase lysosomal enzyme levels in the muscle at any dose used (50-400 micrograms)
  • In cultured macrophages, water-treated chrysotile raised beta-galactosidase release into the medium from about 10% of total culture activity to nearly 50% at 50 micrograms/ml
  • In cultured macrophages, acid-leached chrysotile raised lysosomal enzyme release from about 10% only to 20% of total culture activity
  • Lactate dehydrogenase measurements gave no evidence that either type of asbestos was toxic to the cultured macrophages
  • Comparison materials: zymosan caused a dose-dependent rise in muscle lysosomal enzyme activity; latex caused no release of acid hydrolases from cultured macrophages over 24 h at concentrations up to 1000 micrograms/ml
• The authors' conclusion: The authors concluded that removing surface magnesium from chrysotile by acid treatment greatly diminished its ability to cause inflammation and selective release of lysosomal enzymes. More generally, they concluded that agents that cause inflammation induce this enzyme release from cultured mouse macrophages.
• Limitations the authors state:
  • The authors stated that further work is needed to explain how selective enzyme release by inflammatory stimuli relates to the development of chronic inflammatory lesions
  • The authors noted that differences in particle size or form could explain the differences between materials. They reported similar findings with latex particles up to 15.8 micrometres, and that acid-leached chrysotile keeps its fibrous form.

Topics

Medical terms in this study, explained in our Lexicon: Macrophage, Chronic Inflammation, Chrysotile, Inflammation.

Related studies

• Spontaneous lysosomal enzyme secretion by a murine macrophage-like cell line — W. Jessup, R.T. Dean (1980)
• Lysosomal enzyme secretion by macrophages during intracellular storage of particles — R.T. Dean, W. Hylton, et al. (1979)
• Effects of asbestos and beryllium on release of alveolar macrophage enzymes — K.Y. Kang, D. Bice, et al. (1979)
• Asbestos induces selective release of lysosomal enzymes from mononuclear phagocytes — P. Davies, A.C. Allison, et al. (1974)
• Size-dependent superparamagnetic iron oxide nanoparticles dictate interleukin-1β release from mouse bone marrow-derived macrophages — S. Chen, S. Chen, et al. (2018)
• Degradation of cartilage proteoglycan and collagen by synovial cells. Stimulation by macrophages under activation by phagocytosis, lymphocyte factors, bacterial products or other inflammatory stimuli — C. Peeters-Joris, G. Vaes (1984)

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