The Study On Effects And Related Mechanisms Of Fine Particulate Matter From Cooking Oil Fumes On Lung In Mice With Subacute Exposure

Objective: In order to investigate the effect of fine particulate matter from cooking oil fumes on lung injury and the possible mechanism of injury.Methods: 1.Thefine particulate matter from cooking oil fumes were collected by the PM_2.5 sample,were determined the weight by desiccant method.After the extraction of PM_2.5,the DMSO was diluted to the concentration of 200mg/ml,and then put into the brown wide mouth bottle,and then stored in the refrigerator at-80℃。2.The PM_2.5was diluted with normal saline into different concentrations,respectively,low dose group（1.0mg/ml）,middle dose group（5.0mg/ml）,high dose group（25.0mg/ml）and normal saline control group.The mice were exposed by PM_2.5intracheal instillation for 4 weeks,each interval 48 h.3.The mice were killed 24 h at the end of the experimental,then collected the lung and the BALF of the mice.Weobserved the pathological changes of lung tissue in mice by HE staining,and the oxidative stress,inflammation and apoptosis were detected,the expression of related proteins was detected by Western blot.Results: 1.Pathological examination showed the micealveolar fracture ofhigher dose groupruptureing,there were red blood cell exudation in alveolar cavity and interstitial tissue of lung.Pulmonary interstitial edema was significantly widened,and inflammatory cells aggregated and infiltrated in the lung.2.Compared with the control group,the activity of superoxide dismutase（SOD）in lung tissue of mice exposed to the high dose was significantly decreased（p<0.05）.Compared with the control group,the levels of glutathione peroxidase（GSH-Px）activity in the lung tissue of the middle dose group and the high dose group decreased significantly（P < 0.05）.3.Compared with the control group,the total number of cells in the BALF exposed to the high dose groupincreased significantly（P < 0.05）;thetotal protein contentin the BALF exposed to the high dose group increased significantly（P < 0.05）;onlythe total white blood cellsin the BALF exposed to the high dose group increased significantly（P < 0.05）;the reactive oxygen species（ROS）levelin the BALF exposed tothe middle dose group and the high dose group were significantly increased（P < 0.05）.4.Compared with the control group,the TNF-α m RNA expression level in lung tissue of mice exposed to thelow dose group and the high dose groupsignificantly increased（P < 0.05）;the IL-6 m RNA expression level in lung tissue of mice exposed to the low dose group and the high dose group significantly increased（P < 0.05）;only the IL-6 m RNA expression level in lung tissue of mice exposed to the high dose group significantly increased.5.Wefound that cooking fume PM_2.5 low dose group can be seen in a small amount of TUNEL positive cells of yellow or brown yellow,cooking high dose of PM_2.5 group can see a large number of TUNEL positive cells in bronchial epithelial cells and alveolar epithelial cells by TUNEL stainin,exposed to cooking fume PM_2.5 with higher doses,TUNEL positive cells increased.6.We detectedthe lung tissue tight junction protein in each dose group,including ZO-1,Occludin and Claudin-4 protein expression level,results showed that compared with the control group,ZO-1,Occludin and Claudin-4 protein expressionof the high dose group significantly decreased（P < 0.05）;only the expression of Claudin-4 protein of the middle dose group significantly decreased（P < 0.05）.There was no significant difference in protein expression level in the low dose group.Detection of each dose group of MAPK pathway proteins,namely ERK1/2,p-ERK1/2,p38,p-p38,JNK1/2,p-JNK1/2 protein expression level,results showed that the cooking fume PM_2.5 high dose group compared with the control group,p-ERK1/2 / ERK1/2,p-p38/p38,p-JNK1/2 / JNK1/2 significantly increased（P<0.05）.There was no significant difference in protein expression between middle dose group and low dose group.Conclusion: Exposured in high dose PM_2.5 of cooking fume can cause injury of lung andimpaires of alveolar epithelial barrier function.Cooking oil fumes-derived PM_2.5can result in oxidative stress,inflammation and apoptosis,the activation of MAPK signaling pathway is closely related to the injuryof fine particulate matter from cooking oil fumes on lung.