Dataset Information

Crystalline silica particles cause rapid NLRP3-dependent mitochondrial depolarization and DNA damage in airway epithelial cells.

ABSTRACT: BACKGROUND:Respirable crystalline silica causes lung carcinomas and many thousand future cancer cases are expected in e.g. Europe. Critical questions are how silica causes genotoxicity in the respiratory epithelium and if new cases can be avoided by lowered permissible exposure levels. In this study we investigate early DNA damaging effects of low doses of silica particles in respiratory epithelial cells in vitro and in vivo in an effort to understand low-dose carcinogenic effects of silica particles. RESULTS:We find DNA damage accumulation already after 5-10?min exposure to low doses (5??g/cm2) of silica particles (Min-U-Sil 5) in vitro. DNA damage was documented as increased levels of ?H2AX, pCHK2, by Comet assay, AIM2 induction, and by increased DNA repair (non-homologous end joining) signaling. The DNA damage response (DDR) was not related to increased ROS levels, but to a NLRP3-dependent mitochondrial depolarization. Particles in contact with the plasma membrane elicited a Ser198 phosphorylation of NLRP3, co-localization of NLRP3 to mitochondria and depolarization. FCCP, a mitochondrial uncoupler, as well as overexpressed NLRP3 mimicked the silica-induced depolarization and the DNA damage response. A single inhalation of 25??g silica particles gave a similar rapid DDR in mouse lung. Biomarkers (CC10 and GPRC5A) indicated an involvement of respiratory epithelial cells. CONCLUSIONS:Our findings demonstrate a novel mode of action (MOA) for silica-induced DNA damage and mutagenic double strand breaks in airway epithelial cells. This MOA seems independent of particle uptake and of an involvement of macrophages. Our study might help defining models for estimating exposure levels without DNA damaging effects.

SUBMITTER: Wu R

PROVIDER: S-EPMC7418441 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Crystalline silica particles cause rapid NLRP3-dependent mitochondrial depolarization and DNA damage in airway epithelial cells.

Wu Rongrong R Högberg Johan J Adner Mikael M Ramos-Ramírez Patricia P Stenius Ulla U Zheng Huiyuan H

Particle and fibre toxicology 20200810 1

<h4>Background</h4>Respirable crystalline silica causes lung carcinomas and many thousand future cancer cases are expected in e.g. Europe. Critical questions are how silica causes genotoxicity in the respiratory epithelium and if new cases can be avoided by lowered permissible exposure levels. In this study we investigate early DNA damaging effects of low doses of silica particles in respiratory epithelial cells in vitro and in vivo in an effort to understand low-dose carcinogenic effects of sil ...[more]

PMID: 32778128

Similar Datasets

Project description:The effect, if any, of age on the pulmonary toxicity induced by Min-U-Sil 5 crystalline silica exposure was investigated in rats. As part of the study, the changes in global gene expression profiles in the blood and lungs of the animals were determined. To conduct these studies, to determine if age influences the pulmonary response to crystalline silica exposure, two different age groups of healthy, male F344 rats were used. In this study the young age group of rats (6 months old at the time of exposure) was exposed to either air or crystalline silica (Min-U-Sil 5) (15 mg/m3, 6 hours/day, 5 days) by whole body inhalation. The young age group of rats simulates a group of workers who would be 18 to 20 years old. At two crystalline silica post-exposure time periods (1-day and 6-months) animals were euthanized and pulmonary inflammatory, cytotoxic, and oxidant responses were determined. Analysis of bronchoalveolar lavage parameters of toxicity such as oxidant generation and inflammation revealed significant changes in pulmonary toxicity in the crystalline silica exposed rats compared with the time-matched, air exposed control rats. The blood gene expression profiles showed only minimal changes, at both the time points, in the crystalline silica exposed rats compared with the controls. Specifically, there were a total of 5 genes significantly differentially expressed (fold change >1.5 and FDR p<0.05) in the one-day post-exposure group and no significantly differentially genes in the 6-month post-exposure group. However, the lung gene expression profiles showed substantial changes in the crystalline silica exposed animals at both one-day and 6-month post-exposure. Specifically, there were a total of 385 genes significantly differentially expressed (fold change >1.5 and FDR p<0.05) at the one-day post-exposure group and 317 genes significantly differentially expressed at the 6-month post-exposure. The data obtained from the present study demonstrated that crystalline silica inhalation exposure, under the conditions employed in the present study, resulted in significant changes in lung toxicity parameters and lung gene expression profile in the rats at both 1-day and 6-month post-exposure.

Dataset Information

Crystalline silica particles cause rapid NLRP3-dependent mitochondrial depolarization and DNA damage in airway epithelial cells.

Publications

Crystalline silica particles cause rapid NLRP3-dependent mitochondrial depolarization and DNA damage in airway epithelial cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets