Establishing a Silicosis Rat Model via Exposure of Whole-Body to Respirable Silica
Summary
This study describes a technique to establish a silicosis rat model with the inhalation of silica through the whole body in an inhalation chamber. The rats with silicosis could closely mimic the pathological process of human silicosis in an easy, cost-effective manner with good repeatability.
Abstract
The major cause of silicosis is the inhalation of silica in the occupational environment. Despite some anatomical and physiological differences, rodent models continue to be an essential tool for studying human silicosis. For silicosis, the classic pathological process needs to be inducible via the inhalation of freshly generated quartz particles, which means specifically inducing human occupational disease. This study described a technique to establish and effectively mimic the pathological dynamic evolution process of silicosis. Further, the technique had good repeatability with no surgery involved. The inhalation exposure system was fabricated, validated, and used for toxicology studies on respirable particle inhalation. The critical components were as follows: (1) bulk dry SiO2 powder generator adjusted with an air-flow controller; (2) 0.3 m3 whole-body inhalation exposure chamber accommodating up to 3 adult rats; (3) a monitoring and control system for regulating oxygen concentration, temperature, humidity, and pressure in real-time; and (4) a barrier and waste disposal system for protecting laboratory technicians and the environment. In summary, the present protocol reports the inhalation via the whole body, and the inhalation chamber created a reliable, reasonable, and repeatable rat silicotic model with low mortality, less injury, and more protection.
Introduction
Silicosis, which is caused by the inhalation of silica, is the most serious occupational disease in China, accounting for more than 80% of the total number of occupational disease reports every year1. The etiology of silicosis is clear, and it can be prevented and controlled, but no effective treatment method is available2. Many drugs have been proven to be effective in basic studies, but they have imprecise clinical effects3,4. Therefore, the pathological and physiological mechanisms of silicosis still need to be explored.
Many studies have used a one-time infusion of silica into the trachea of rats or mice to investigate the pathogenesis of silicosis5,6. Although these rodent silicotic models could be obtained in a short time7, these methods still had challenges, such as animal trauma and high mortality. Some studies have involved instilling stored silica into the lungs to induce a nonspecific lung reaction, but did not mention silicotic nodules in mice8. Furthermore, away from acute silicosis, chronic exposure to silica in occupational environments induced significantly lower pulmonary inflammation and elevated the levels of anti-apoptotic markers, rather than pro-apoptotic markers, in the lungs9. Therefore, a reliable, reasonable, and repeatable animal model is needed to explore the pathogenesis of silicosis further.
The present study describes a method to mimic the disease process of patients with silicosis through silica inhalation via the whole body, air-delivered particles in an inhalation chamber, which comprised an air-delivered silica generator, a whole-body chamber, and a waste disposal system. This method is simple, easy to operate, and effectively mimics the pathological dynamic evolution process of silicosis. Also, many possible mechanisms and the pathogenesis of silicosis are identified using this method10,11,12. The proposed protocol is anticipated to help further investigations in the related field of silicosis research.
Protocol
Representative Results
Discussion
As the leading cause of silicosis, silica plays a decisive role in molding. The silica particles inhaled by patients with pneumoconiosis are fresh, free silica particles produced by mechanical cutting. Silica can generate reactive oxygen species either directly on freshly cleaved particle surfaces or indirectly through its effect on the macrophages25. Therefore, the grinding of silica particles is of high importance. In the proposed protocol, silica was ground with agate mortar for more than 90 mi…
Divulgaciones
The authors have nothing to disclose.
Acknowledgements
This work was funded by the National Natural Science Foundation of China (82003406), the Natural Science Foundation of Hebei Province (H2022209073), and the Science and Technology Project of Hebei Education Department (ZD2022127).
Materials
| Air detector (compressive atmospheric sampler) | Qingdao Xuyu Environmental Protection Technology Co. LTD | ||
| Anatomical table | No specific brand is recommended. | ||
| Antibody of CD68 | Abcam | ab201340 | |
| DAB | ZSGB-BIO | ZLI-9018 | |
| Electric heating air-blowing drier | Shanghai Yiheng Scientific Instrument Co., LTD | ||
| Electronic balance | OHRUS | ||
| Embedding machine | leica | ||
| Exhaust gas discharge device | HOPE Industry and Trade Co. Ltd. | ||
| Generator systems | HOPE Industry and Trade Co. Ltd. | ||
| Gloves (thin laboratory gloves) | The secco medical | ||
| Hematoxylin and eosin | BaSO Diagnostics Inc. | BA4025 | |
| HOPE MED 8050 exposure control apparatus | HOPE Industry and Trade Co. Ltd. | ||
| Inhalation chamber | HOPE Industry and Trade Co. Ltd. | ||
| Injection syringe | No specific brand is recommended. | ||
| Light microscope | olympus | ||
| Object slide | shitai | ||
| PV-6000 (HRP-conjugated goat anti-mouse IgG polymer) | Beijing Zhongshan Jinqiao Biotechnology Co. Ltd | s5631 | |
| Silicon dioxide | Sigma-Aldrich | ||
| Slicing machine | leica | RM2255 | |
| Waste gas treatment device | HOPE Industry and Trade Co. Ltd. | ||
| Wet box | Cooperative plastic Products Factory | ||
| Xylol | Tianjin Yongda Chemical Reagent Co., LTD |
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