The Role Of EGFR In The Acute Lung Injury Induced By Cardiopulmonary Bypass

Cardiopulmonary bypass(CPB)has become a very important technique in cardiac surgery.The development of cardiopulmonary bypass(CPB)cardiac surgery has revolutionized and improved the prognosis of patients.However,CPB itself will cause some inevitable systemic inflammatory reaction,leading to a series of complications.To this end,we designed the following experiments to investigate the mechanism of inflammatory response after cardiopulmonary bypass and possible treatment option.Materials and methods1.Establishment of cardiopulmonary bypass model:the thoracic aorta was opened along the sternum of the rabbit,and the 6F catheter was inserted into the aorta via the aorta.The distal end of the catheter was along the descending aorta.At the beginning of the flow,the clamp clamps the aorta and the pulmonary artery completely,and the Thomas fluid was injected to aorta and maintain the temperature of 33 degrees.30mins after the cardiac arrests,open the thoracic and pulmonary artery,termination of cardiopulmonary bypass,neutralization of heparin,monitoring vital signs,observation for 4 hours.2.Groups:The experiment was divided into 4 groups:CTRL group(preoperative oral 15%Captisol 6.25ml/Kg for 3 hours,thoracotomy without cardiopulmonary bypass);Erlotinib group(preoperative oral Erlotinib for 3 hours,the thoracotomy without cardiopulmonary bypass);CPB group(preoperative oral 15%Captisol 6.25ml/Kg for 3 hours,cardiopulmonary bypass surgery)and CPB+Erlotinib group(oral Erlotinib 3 hours before operation,cardiopulmonary bypass surgery)3.ELISA method was used to detect the expression of TNF-a in the serum of rabbits.The expression of TNF-a was detected by enzyme linked immunosorbent assay(ELISA).4.Immunofluorescence was used to detect the expression of PARP-1 in the lung tissues of rabbits.The expression of PARP-1 were detected by immunofluorescence assay.5.Western blot was used to detect the expression of phosphorylated protein ERK1/2 and P38 in each group:samples were collected 4 hours after operation and the expression of phosphorylated protein ERK1/2 and P38 was detected by Western blot method.6.Statistical analysis data analysis was performed by SPSS 20.0 software.Data were expressed as mean ± standard deviation(SD).Single factor at two different time-points were assessed by using repeat measurement.Comparation between two groups was tested by independent samples t test and comparation among multiple groups were tested by one way ANVOA.If equal variance assumed,we chose LSD test for post hoc multiple comparisons,if not,then we used Dunnett's T3.P<0.05 was considered statistically significant.Figures were made by using GraphPad Prism 5.0 drawing software.Results1.The influence of cardiopulmonary bypass on the death of lung cellsCompared with CTRL,the expression level of CPB in lung tissue of PARP-1 cells up-regulated significantly(p<0.001).2.Effect of EGFR inhibitor on TNF-a induced by cardiopulmonary bypass.Arterial blood was collected 4 hours after operation in each group,and the expression level of TNF-a was detected by enzyme-linked immunosorbent assay(ELISA).Compared with CTRL,the TNF-a expression level of CPB and CPB+Erlotinib group were increased significantly in arterial blood(p<0.001);compared with CTRL group and Erlotinib group,no significant difference between the expression level of TNF-alpha(P=0.974).Compared with CPB,the expression level of TNF-? was significantly lower in the CPB+Erlotinib group(p<0.001).3.Effects of EGFR inhibitors on phosphorylation of ERK1/2 and P38Compared with CTRL group,the phosphorylation level of ERK1/2 in CPB group and CPB+Erlotinib group was significantly higher(p<0.001),but there was no significant difference between ERK1/2 group and Erlotinib group(p =0.656).Compared with CPB group,the phosphorylation level of ERK1/2 in CPB+Erlotinib group was significantly reduced,and the difference was statistically significant(p<0.001).Compared with CTRL group,the phosphorylation level of CPB(p<0.001)and CPB+Erlotinib group(p<0.05)was significantly higher than that of group P38(P38),but there was no significant difference in the phosphorylation level of Erlotinib(p =0.277).Compared with group CPB,the phosphorylation level of P38 in CPB+Erlotinib group was significantly reduced,and the difference was statistically significant(p<0.05).Conclusions1.The level of TNF-? was significantly increased after cardiopulmonary bypass,and Parthanatos were found in a large number of lung cell.2.Epidermal growth factor receptor is involved in the formation of TNF-?induced by cardiopulmonary bypass.3.The levels of inflammatory response in vivo induced by extracorporeal circulation increased,the possible mechanism is the activation of EGFR,which can activate MAPK signaling pathway of ERK1/2 and P38 induced ERK1/2 and P38 phosphorylation,to promote the production and release of TNF-? and the process of inflammatory response.