Low Expression Of SUB1 Gene In Peripheral Blood Mononuclear Cells Of Patients With Acute Myocardial Infarction

Background and ObjectiveMyocardial infarction（MI）is a global threatening disease.It is estimated that 5 million people in the United States have emergency treatment for acute chest pain every year,and more than 800000 people suffer from acute myocardial infarction（AMI）,of which 27% die（mostly before arriving at the hospital）.Many studies have confirmed that myocardial infarction is closely related to heredity,and inflammatory response plays an important role in the occurrence and development of myocardial infarction.In the previous gene chip of the research group,it was found that the expression level of SUB1 gene in peripheral blood leukocytes of patients with AMI was lower than that of patients with stable coronary atherosclerotic disease（SCAD）.SUB1 can recruit rapidly at the site of DNA damage,combine with the early and transient site of DNA damage,play a role in detecting and / or exposing DNA damage,and can specifically protect DNA from oxidative damage to reduce chronic inflammation,which may reduce the risk of AMI.The purpose of this study is to verify the difference of gene expression level in larger samples and evaluate whether the expression level of SUB1 gene in peripheral blood can be used as a biomarker to judge the occurrence of AMI in SCAD patients.MethodThis study collected the peripheral blood of 75 SCAD patients and 113 AMI patients hospitalized in the Department of cardiovascular medicine of China Japan Friendship Hospital of Jilin University.The expression of SUB1 gene at mRNA level was detected by real-time fluorescence quantitative polymerase chain reaction（PCR）,and the expression level of SUB1 gene was detected by Western blot analysis at protein level.ResultThe clinical data of group MI and group SCAD showed that: gender,history of diabetes,history of hypertension,smoking history,serum triglyceride,serum total cholesterol,and low-density lipoprotein cholesterol.There was no significant difference in high-density lipoprotein cholesterol（HDL-C）between the two groups.However,the age of AMI group was significantly older than that of SCAD group,P = 0.012;In fasting blood glucose,the patients with abnormal fasting blood glucose in AMI group were more than those in SCAD group,P = 0.01.In terms of gene and protein levels,the expression level of SUB1 gene in peripheral blood of patients with AMI was significantly lower than that of patients with SCAD（z =-2.095,P 0.036）,and there was no difference in the expression levels between elderly and young subjects,and between hyperglycemia and hypoglycemia.Analysis of the expression level of SUB1 gene in peripheral blood leukocytes of the two groups: the relative expression of SUB1 gene mRNA in peripheral blood of patients in AMI group was significantly lower than that in SCAD group,and its relative expression was 0.47 times higher than that in SCAD group.Regression analysis showed that there was no difference in the expression of SUB1 gene mRNA between the elderly group and the young group（P = 0.65）,and there was no difference between the high glucose group and the normal group（P = 0.65）.There was no correlation between the low expression of SUB1 gene mRNA in peripheral blood of patients with AMI and blood glucose and age.Low expression of SUB1 gene and fasting blood glucose were independent risk factors for AMI.Compared with high expression of SUB1 gene,the risk of AMI in SUB1 gene low expression group increased by 1.959 times.ConclusionThe expression of sub1 gene in peripheral blood mononuclear cells of patients with AMI was significantly lower than that of patients with SCAD.Its low expression was an independent risk factor for AMI in SCAD group.Compared with the high expression of sub1 gene,the risk of AMI in sub1 gene low expression group increased by 1.959 times.The low expression of sub1 gene is considered to be a biomarker for AMI in patients with SCAD.