[Role of pyroptosis pathway related molecules in acute lung injury induced by gas explosion in rats]

Objective: To explore the role and significance of pyroptosis in gas explosion-induced acute lung injury (ALI) in rats. Methods: In February 2018, 126 SPF male SD rats were selected and randomly divided into blank control group (18 rats) and experimental group (40 m, 80 m, 120 m, 160 m, 200 m and 240 m, 18 per group) . The experimental group carried out gas explosion in the roadway to build the ALI model, the control group did not carry out gas explosion, and other conditions were consistent with the experimental group. Respiratory function indexes such as respiratory frequency (f) , tidal volume (TV) , minute ventilation (MV) and airway stenosis index (Penh) were measured 24 hours after the explosion. 5 rats in each group were sacrificed after anesthesia, Hematoxylin-Eosin (HE) staining was used to observe the pathological morphology of lung tissue. Immunohistochemistry was used to detect the content of Caspase-1. Western blotting was used to detect the content of cell pyroptosis including nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) , Caspase-1, interleukin-1β (IL-1β) and interleukin-18 (IL-18) in lung tissue related protein expression. Results: The f and MV of rats in the experimental group were higher than those in the control group (P<0.05) . Except for the 40 m and 80 m groups, the TV of rats in the other experimental groups were higher than those in the control group (P<0.05) . Except for the 40 m group, the Penh of rats in the experimental groups were lower than those in the control group (P<0.05) . HE staining showed that the lung tissue of the experimental groups at different distance points showed obvious edema of the pulmonary interstitium and alveoli, a large number of red blood cells and inflammatory cells exuded in the alveolar space, thickening of the pulmonary interstitium, and increased lung injury score (P<0.05) . The results of immunohistochemistry showed that the positive expression of Caspase-1 in each experimental group was higher than that in the control group (P<0.05) . Western blotting results showed that the expression of pyroptosis-related proteins in each experimental group was higher than that in the control group (P<0.05) . Conclusion: Pyroptosis is involved in the pathophysiological process of gas explosion-induced ALI in rats.