The role of autophagy in pulmonary inflammatory response in silicosis model rats
10. 20001/j. issn. 2095⁃2619. 20224006
- Author:
zhang yu
;
geng xiao
;
sai linlin
- Publication Type:Journal Article
- Keywords:
Inflammatory response；Silicosis；Silica；Autophagy；Rapamycin；3-Methyladenine；Rats
- From:
China Occupational Medicine
2022;49(2):153-157
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the role of autophagy in inflammatory response in the lungs of silicosis rats. Methods The
specific pathogen-free healthy male Wistar rats were randomly divided into four groups with 10 rats in each group. The rats in the
control group were given an equal volume of 0.9% sodium chloride solution; all rats in the silicon dioxide (SiO2
) group, the SiO2
+
3-methyladenine (3-MA) group, and the SiO2
+rapamycin (RAPA) group were given a mass concentration of 0.05 mg/L of SiO2
suspension (1.0 mL/rat) to establish a rat model of silicosis using non-exposed tracheal instillation method. Two days before
SiO2 exposure, the rats in SiO2
+3-MA group were intraperitoneally injected with 3-MA at a dose of 2.5 mg/kg body weight. The rats
in the SiO2
+RAPA group were intraperitoneally injected with a dose of RAPA 1.0 mg/kg body weight, once a day, and once every
other day after modeling, for a total of 10 injections. The pathological changes in the lung tissue of the rats in each group were
evaluated using hematoxylin-eosin and Masson staining. The relative expression levels of transforming growth factor-β (TGF-β) ,
interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the lung tissue of the rats in each group were detected using
enzyme-linked immunosorbent assay. The relative expression levels of microtubule-associated protein 1 light chain 3 (LC3) and
yeast autophagy-related gene 6 (Beclin1) in lung tissue of rats in each group were detected by Western blotting. Results The
pathological observation of rat lung tissue showed that scattered inflammatory nodules and interstitial inflammatory cells were
found in the lung tissue of the rats in the SiO2 group. In the SiO2
+3-MA group, the inflammation in the lung tissue was more
severe and the alveolar cavity had viscous secretions. The rats in the SiO2
+RAPA group had less inflammation and smaller
inflammatory nodules than the SiO2 group. Compared with the control group, the TNF-α, IL-1β, TGF-β, Beclin1 protein relative
expression levels and LC3 Ⅱ/Ⅰ ratio in the lung tissue were increased in the SiO2 group (all P<0.05). Compared with the SiO2
group, the relative expression levels of TGF-β and TNF-α in the lung tissue of the rats increased (all P<0.05), and the ratio of
LC3 Ⅱ/Ⅰ and Beclin1 protein relative expression decreased in the SiO2+3-MA group (all P<0.05). Compared with the SiO2+
3-MA group, the relative expression levels of TNF- α, IL-1β and TGF- β in the lung tissue of the SiO2
+RAPA group were
decreased (all P<0.05), and the LC3Ⅱ/Ⅰ ratio and the relative expression level of Beclin1 protein were increased (all P<0.05).
Conclusion Autophagy occurs when inflammatory reaction occurs in the lungs of silicosis model rats; autophagy has inhibitory
effect on pulmonary inflammation.
