| Objective: Acute myocardial infarction(AMI)lacks an effective diagnostic marker at an early stage,and miRNA-208 a may be an early diagnostic indicator for AMI.The aim of this study was to provide a reference for the subsequent development of AMI diagnostic kits by studying the changes in miRNA-208 a in animal models and further studying the expression levels and trends of plasma in AMI patients.Methods:(1)This study included 21 healthy volunteers and 41 patients with acute chest pain(ACP).Patients with ACP were divided into AMI group(n=21)and acute angina(AP)group according to follow-up test(n=20).Venous blood was collected at 3h,6h,12 h and 24 h after admission.In the other AMI group,12 patients underwent PCI.The venous blood was collected from 3-6 h after operation,and the fasting venous blood was collected from the control group in the morning.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the expression level and trend of miRNA-208 a in plasma of patients,and to detect troponin ?(cTn?)and creatine kinase isoenzyme(CK-MB)in patients' blood.The expression level is analyzed by the corresponding statistical method.(2)30 male rats were selected and divided into 3 groups.The AMI group was established by classical open thoracotomy of the left anterior descending coronary artery(LAD).The sham operation group was the same as AMI,but at the time of ligation.Only threading was not ligated;non-surgical group: no treatment.Rat venous blood was collected at 3h? 6h? 12 h and 24 h.Real-time fluorescence quantitative polymerase chain reaction was used to detect the expression level and change trend of miRNA-208 a in rat plasma.Calcium protein I(cTn?)and myoglobin(Mb)expression levels were analyzed using statistical methods.Results: The level of miRNA-208 a in the AMI group was significantly higher than that in the AP group and the control group(P<0.05).The miRNA-208 a level in the serum of patients was significantly increased compared with the time of admission,and peaked at 3 hours,then gradually decreased,and returned to normal level with 12-24 hours.There were significant differences between the AP group and the control group at 3h,6h and 12h(P<0.05).Plasma miRNA-208 a expression levels were significantly lower in patients undergoing PCI than in admission(P < 0.05).Correlation analysis showed a low positive correlation between the level of miRNA-208 a in serum and the expression level of creatine kinase I(CK-MB).After ligation of the anterior descending coronary artery,the level of miRNA-208 a in the serum increased rapidly after surgery and reached the peak at 12 h,3h?6h?12h?24h and the control group.There was a statistically significant difference(P<0.05).The troponin increased at 3-6h after LAD ligation,reached the peak at 24 h,and decreased slowly at 48-72 h.Compared with the control group at 6 h?12h?24h and 48 h,there was obvious Statistical difference(P< 0.05).Myoglobin reached the peak at 6-12 h after ligation,and decreased rapidly at 24-48 h.There was significant difference between the 3h?6h,?12h and 24 h comparing with the control group(P<0.05).Conclusion: Early plasma miRNA-208 a levels were significantly elevated in patients with AMI.And its elevation is related to certain clinical indicators.miRNA-208 a can be used as a biochemical marker for the diagnosis of early myocardial infarction.This study provides a new perspective for the early diagnosis and treatment of AMI,and also provides a reference for the development of AMI early diagnostic kits. |
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