Expression Of SGK1 In Coronary Artery Thrombus And Peripheral Arterial Blood From Patients With ST-elevation Myocardial Infarction

Objective: STEMI(Acute ST-segment elevation myocardial infarction)refers to acute myocardial ischemic necrosis,which is the most serious type of coronary heart disease and the main cause of disability and death.The incidence of STEMI in China was increasing year by year and has become one of the major public health problems.In recent years,inflammatory response has been found to be one of the important mechanisms involved in STEMI.SGK(serum-and glucocorticoid-inducible kinase),a member of the serine/threonine protein kinase gene family,is made up of three homologous isomers,containing SGK1,SGK2 and SGK3,among which SGK1 is very important for the maintenance of life activities.Studies have found that SGK1,as an important downstream molecule of PI3 K,promoted the inflammatory response to give rise to the occurrence and development of atherosclerosis,but the correlation between SGK1 and STEMI has not been reported.In recent years,as the develop ment of thrombus aspiration,it provided a reliable and effective way for the study of coronary artery thrombosis.In this study,intra-coronary thrombosis obtained from percutaneous coronary interventional therapy(PCI)in the emergency treatment of STEMI patients and thrombus prepared in vitro were observed by HE staining and immunohistochemical staining.Besides,peripheral artery blood of the STEMI group and the control group was collected to extract proteins for western blotting,and then to analyze the basic components of coronary artery thrombus,and the expression of SGK1 in thrombus and peripheral artery blood,so as to explore the correlation between SGK1 and STEMI.Methods: A total of 32 patients with acute myocardial infarction,who were admitted to the second affiliated hospital of Dalian medical university and affiliated hospital of Hangzhou normal university from December 2018 to July 2019 and underwent emergency PCI and thrombus aspiration,whose thrombus components and peripheral arterial blood being obtained effectively,were selected as the thrombus group.While 32 healthy people whose peripheral arterial blood being obtained,were selected as the control group.In the the thrombus group: STEMI of 32 cases were put into 4% paraformaldehyde phosphate buffer for being fixed 24 to 48 hours after paraffin embedding,serial section with HE staining and immunohistochemical staining.Specific antibody was used to label platelet and SGK1 in thrombosis,the percentage of positive specific antibody markers area in each slice is calculated by using the Image J,to reflect the expression degree of SGK1.After that,5ml peripheral arterial blood was preserved in EDTA anticoagulant tube and under-80℃ environment.Protein imprinting technology was used to separate the protein samples by polyacrylamide gel electrophoresis,and then transferred to nitrocellulose membrane,and then specific SGK1 protein antibody was applied to test target protein by immunological reaction,for analyzing expression level of SGK1 in thrombus.In the control group,6ml peripheral arterial blood of 32 healthy people underwent normal coronary angiography was collected,of which 1ml was placed in EDTA anticoagulant tube,which was incubated in 37℃ cell culture medium for 6 hours after adding 1ml recombinant human tissue factor solution,to obtain control thrombus.Another 5ml peripheral arterial blood was placed in an EDTA anticoagulant tube and stored at-80℃.The analysis method was the same as that of the STEMI group.Results: A total of 32 patients in STEMI group received intracoronary aspirates,of which 22 were simple thrombus specimens without plaque components.And we classified The 22 thrombus specimens by naked eye.Of these 22 cases underwent thrombus aspiration,18 cases were red thrombus(81.8%),2 cases were white thrombus(9.1%),and 2 cases were mixed thrombus(9.1%).The coronary thrombosis contained a large number of red blood cells,fibrinogen and platelets,among which red blood cells were the main cell components of the thrombus,followed by platelets.Moreover,the distribution of red blood cells and platelets in the thrombus is characterized by "mutual overlapping".Compared with the control thrombus,the expression of SGK1 in coronary thrombus was significantly increased in patients with STEMI.And SGK1 in thrombus was expressed mainly in platelets and distributing around the thrombus.The application of western blotting method has revealed that expression of SGK1 in peripheral blood of STEMI patients was significantly higher than that in healthy people.Conclusions: The expression of SGK1 in coronary artery thrombosis and peripheral artery blood of patients with STEMI was significantly higher than that in the control group,and it was highly expressed in the platelet of the thrombus.SGK1 may be involved in Initiating STEMI by mediating inflammatory and platelet chemotaxis and aggregation.