Effects Of Activation Of ALDH2 On Inflammasome In High Glucose-induced Lung Injury

Objective: To observe diabetes induce lung injury in rats model and high glucose induced pulmonary alveolar type II epithelial A549 cells injury,and investigate the effects of activation of aldehyde dehydrogenase 2(ALDH2)on the changes of NLRP3 inflammasome.Methods: Type I diabetic rats were prepared and grouped into 4 groups:(1)Control group(CON group);(2)ALDH2 agonist low dose ethanol group(Et OH group);(3)Diabetes group(DM group);(4)Diabetes + Et OH group(DM+Et OH group),the rats were feeded for 6 weeks and 12 weeks respectively.The lung wet weight and body weight of the rats were weighed,and the lung coefficient was calculated;the lung morphology was observed by HE staining method;the changes of lung fibrosis were measured by Masson and Sirius red staining methods;the changes of lung ultrastructure was observed through transmission electron microscopy;the protein expressions of ALDH2,and core components of NLRP3 inflammasome-NLRP3,ASC and caspase-1 were detected by western blot method.The alveolar epithelial A549 cells were cultured in vitro and divided into 4 groups: Control group(25 mmol/L highglucose complete medium),ALDH2 agonist 20?mol/L Alda-1 group,ALDH2 antagonist 60?mol/L Daidzin group,20?mol/L Alda-1 + 60?mol/L Daidzin group.After the cells were treated for 24 h,the cell proliferation activity was measured by thiazolyl blue MTT colorimetric assaymethod,and the cellular reactive oxygen species ROS level were detected by DHE fluorescent staining method,the cell migration ability was performed by cell scratching experiments,the protein expressions of ALDH2 and the core components of inflammasome NLRP3,ASC,caspase-1 were detected by western blot.Results: Animal experiments results showed that: Compared with the control group,the lung coefficient of the diabetic group was significantly increased(P<0.05),the pathological changes of the lung tissue were aggravated,the collagen fibers were increased significantly,and the ultrastructural damage was obvious.Compared with the diabetic rats in 6 weeks,the injury degree were more obvious in 12 weeks.The expression of ALDH2 protein was significantly decreased(P<0.05),and the expressions of NLRP3,ASC and caspase-1 protein were significantly increased in the 6-week diabetic group(P<0.05).Compared with the DM group,the pathological changes of lung tissue in the DM+ETOH group were alleviated,collagen fibers were relatively reduced,ultrastructural damage was alleviated,and ALDH2 protein expression was significantly increased(P<0.05).The expressions of NLRP3,ASC and caspase-1 protein were significantly decreased at 6 weeks(P<0.05),and the expressions of inflammasome key components in 12-week diabetic group were inconsistent with 6 weeks.Alveolar type II epithelial A549 cells results showed: Compared with the control group,after adding the ALDH2-specific agonist Alda-1,the cell proliferation activity did not change significantly,but the oxidative stress level and cell migration rate were significantly decreased(P<0.05).ALDH2 protein expression was significantly increased(P<0.05),the expressions of NLRP3,ASC and caspase-1 protein were significantly decreased(P<0.05).After Daidzin blocked ALDH2 specifically,there were no significant changes in cell proliferation,oxidative stress,cell migration rate,ALDH2 and ASC protein expressions,while NLRP3 protein expression was significantly increased(P<0.05),and caspase-1 protein expression was significantly decreased(P<0.05).Compared with Alda-1 group,there was no significant changes in cell proliferation and oxidative stress in Alda-1+Daidzin group,but cell migration rate was significantly increased(P<0.05),ALDH2 protein expression was decreased(P<0.05),and the protein expressions of NLRP3,ASC and caspase-1 were significantly increased.(P<0.05).Conclusion: In diabetic rats,the ALDH2 expression in lung tissue was decreased,and the expression of inflammasome was increased.activation of ALDH2 by low concentration of ethanol attenuated the lung injury in diabetic rats,which may be related to the decrease the expression of NLRP3 inflammasome.Increasing ALDH2 expression in alveolar type II epithelial A549 cells attenuated high glucose-induced cell damage,which may be achieved by reducing cellular ROS levels and reduce the expression of inflammasome.