Autophagy changes in lung tissues of mice at 30 days after carbon black‐metal ion co‐exposure

Abstract

Objectives Accumulating studies have investigated the PM2.5‐induced pulmonary toxicity, while gaps still remain in understanding its toxic mechanism. Due to its high specific surface area and adsorption capacity similar to nanoparticles, PM2.5 acts as a significant carrier of metals in air and then leads to altered toxic effects. In this study, we aimed to use CBs and Ni as model materials to investigate the autophagy changes and pulmonary toxic effects at 30 days following intratracheal instillation of CBs‐Ni mixture. Materials and methods Groups of mice were instilled with 100 µL normal saline (NS), 20 µg CBs, and 4 µg Ni or CBs‐Ni mixture, respectively. At 7 and 30 days post‐instillation, all the mice were weighed and then sacrificed. The evaluation system was composed of the following: (a) autophagy and lysosomal function assessment, (b) trace element biodistribution observation in lungs, (c) pulmonary lavage biomedical analysis, (d) lung histopathological evaluation, (e) coefficient analysis of major organs and (f) CBs‐Ni interaction and cell proliferation assessment. Results We found that after CBs‐Ni co‐exposure, no obvious autophagy and lysosomal dysfunction or pulmonary toxicity was detected, along with complete clearance of Ni from lung tissues as well as recovery of biochemical indexes to normal range. Conclusions We conclude that the damaged autophagy and lysosomal function, as well as physiological function, was repaired at 30 days after exposure of CBs‐Ni. Our findings provide a new idea for scientific assessment of the impact of fine particles on environment and human health, and useful information for the comprehensive treatment of air pollution.

An In Vitro Model to Assess Early Immune Markers Following Co-Exposure of Epithelial Cells to Carbon Black (Nano)Particles in the Presence of S. aureus: A Role for Stressed Cells in Toxicological Testing

“…In addition, nearly 20 years ago, Jakab et al confirmed that combinations of CB and formaldehyde or acrolein compromised lung host defence by suppressing killing and phagocytosis of S. aureus [36,52]. Furthermore, recent studies of CB exposure in mice studied over 30 days confirm increased autophagy after 7 days, which is reversible after 30 days [53,54]. These studies and our own confirm the importance of studying exposure to injured, stressed, or infected cells.…”

An In Vitro Model to Assess Early Immune Markers following Co-Exposure of Epithelial Cells to Carbon Black (nano)Particles in the Presence of S. Aureus: Differential Induction of Cytokines.

“…In addition, nearly 20 years ago Jakab et al con rmed that combinations of CB and formaldehyde or acrolein compromised lung host defence by suppressing killing and phagocytosis of S. aureus [32,40]. Furthermore, recent studies of CB exposure in mice studied over 30 days con rm increased autophagy after 7 days which is reversible after 30 days [41,42]. These studies and our own, con rm the importance of studying exposure to injured, stressed or infected cells.…”

Long-Term Pulmonary Damage in Surviving Antitoxin-Treated Mice following a Lethal Ricin Intoxication

“…It should be mentioned that although 30 days PE is considered a long period of time in mice [ 18 , 19 ], the damage (in particular pulmonary damage) could worsen at later stages, i.e., 60 days PE or later [ 20 ]. Vice versa, it could be that following a longer period of time, enhanced tissue repair leads to decreased damage.…”