Crocidolite-induced reactive oxygen metabolites generation from human polymorphonuclear leukocytes

Our plain-English summary of Crocidolite-induced reactive oxygen metabolites generation from human polymorphonuclear leukocytes, by T. Ishizaki, E. Yano, N. Urano, et al (Environmental Research, 1994).

The study

• Authors: T. Ishizaki, E. Yano, N. Urano, P.H. Evans
• Journal: Environmental Research
• Published: 1994;66(2):208-16
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In order to study the mechanism of carcinogenicity of crocidolite asbestos, we have investigated the species of reactive oxygen metabolites (ROM) induced by crocidolite from human polymorphonuclear leukocytes (PMN) utilizing both an electron spin resonance (ESR) spin trapping method with 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and a luminol-dependent chemiluminescence (CL) method. The present study confirms the generation of OH. from human peripheral blood PMN stimulated by UICC crocidolite utilizing ESR. In addition, PMN incubated with 25-400 micrograms/ml of crocidolite produced CL, the intensity of CL increasing in a dose-dependent manner. Superoxide dismutase, catalase, and dimethyl sulfoxide, which are scavengers of O2-, H2O2, and OH., respectively, inhibited the production of crocidolite-stimulated CL from PMN, also in a dose-dependent manner. Sodium azide, an inhibitor of myeloperoxidase (MPO) to produce OCl-, also inhibited CL production. These results suggest the involvement of O2-, H2O2, OH., and OCl- in the production of CL by crocidolite-stimulated PMN. In conclusion, it is proposed that OH. is a key ROM species in the mechanism of crocidolite-induced carcinogenesis.

In plain English

This was a laboratory (in vitro) study of what reactive oxygen metabolites (ROM) human polymorphonuclear leukocytes (PMN) generate when exposed to crocidolite asbestos. The authors used two methods: electron spin resonance (ESR) spin trapping with DMPO, and luminol-dependent chemiluminescence (CL) measured with a luminometer. PMN taken from human peripheral blood and stimulated with UICC crocidolite gave a DMPO-OH signal on ESR, which the authors took as evidence of hydroxyl radical (OH.) generation; adding dimethyl sulfoxide (DMSO) inhibited detection of that signal. PMN incubated with crocidolite produced CL whose intensity rose with the crocidolite concentration. Superoxide dismutase, catalase, DMSO and sodium azide (an inhibitor of myeloperoxidase, which produces OCl-) each inhibited crocidolite-stimulated CL in a dose-dependent way, while heat-inactivated bovine serum albumin did not. The time course of CL with crocidolite fell between that of the soluble stimulant FMLP and the particulate stimulant zymosan. The authors proposed that OH. is a key ROM species in crocidolite-induced carcinogenesis, and said further study of the mechanism was needed.

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 laboratory experiment on human blood cells, using ESR spin trapping and luminol-dependent chemiluminescence
• Who was studied: Polymorphonuclear leukocytes (PMN) isolated from human peripheral blood, studied in suspension
• Exposure: UICC crocidolite asbestos added to PMN suspensions; the article's printed abstract gives a range of 52-400 micrograms per millilitre (the PubMed version of the same sentence reads 25-400 micrograms per millilitre)
• Main results:
  • With PMN stimulated by crocidolite in the presence of DMPO, the DMPO-OH signal was recorded on ESR, which the authors took as confirmation of OH. generation from leukocytes
  • Adding DMSO inhibited detection of the ESR signal (data not shown by the authors)
  • Chemiluminescence from crocidolite-stimulated PMN increased as the crocidolite concentration increased
  • All the ROM scavengers tested (SOD, catalase, DMSO, NaN3) inhibited crocidolite-induced CL from PMN
  • Sodium azide, inhibiting myeloperoxidase (MPO) which produces OCl-, also inhibited CL production
  • Heat-inactivated bovine serum albumin, used as a control protein, did not inhibit the CL production
  • The time course of CL production with crocidolite lay between that of FMLP (early peak) and zymosan (gradual increase)
  • Conditions used in the time-course comparison: PMN 1 x 10^6 cell/ml, crocidolite 500 µg/ml, zymosan 500 µg/ml, FMLP 100 nM
• The authors' conclusion: The authors concluded that their results suggest the involvement of O2-, H2O2, OH. and OCl- in crocidolite-stimulated CL from PMN, and proposed that OH. is a key ROM species in the mechanism of crocidolite-induced carcinogenesis
• Limitations the authors state:
  • Luminol-dependent CL is a non-specific reaction to ROM, so the ROM species are not directly identified by it
  • The authors stated that further study of the mechanism of CL production by crocidolite from PMN is necessary
  • The authors stated that the exact mechanism of asbestos-stimulated CL production from PMN has not been elucidated

Topics

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

Medical terms in this study, explained in our Lexicon: Crocidolite, UICC, Superoxide, Carcinogenesis.

Related studies

• Cellular mechanisms of reactive oxygen metabolite generation from human polymorphonuclear leukocytes induced by crocidolite asbestos — T. Ishizaki, E. Yano, et al. (1997)
• Chemiluminescent detection of induced reactive oxygen metabolite production of human polymorphonuclear leucocytes by anthophyllite asbestos — T. Iwata, N. Kohyama, et al. (2002)
• Production of reactive oxygen metabolites induced by asbestos fibres in human polymorphonuclear leucocytes — M. Hedenborg, M. Klockars (1987)
• Production of reactive oxygen species by man-made vitreous fibres in human polymorphonuclear leukocytes — M. Ruotsalainen, M.R. Hirvonen, et al. (1999)
• Changes in free intracellular calcium and production of reactive oxygen metabolites in human leukocytes by soluble and particulate stimuli — M. Tuomala, M.R. Hirvonen, et al. (1993)
• IgG and IgA enhance the chrysotile-induced production of reactive oxygen metabolites by human polymorphonuclear leucocytes — M. Klockars, M. Hedenborg, et al. (1989)

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