Objective To investigate the association between the proportion of peripheral blood intermediate monocyte subset(Mon2)and prognosis in patients with acute myocardial infarction(AMI)receiving percutaneous coronary intervention(PCI).Methods A total of 100 AMI patients who underwent PCI between March 2021 and June 2022 were enrolled.Peripheral venous blood sam-ples were collected within 24 hours of onset in all patients,and monocyte subsets were analyzed using three-color flow cytometry.Patients were followed up for at least 1 year after discharge,and major ad-verse cardiovascular events(MACE)were recorded.Results The optimal cut-off point for predic-ting MACE occurrence 1 year after PCI in AMI patients based on the Mon2 proportion was 25.65％(area under the curve=0.758,95％CI,0.607 to 0.909,P=0.002),with a sensitivity of 64.3％and a specificity of 86.0％.Patients were divided into high Mon2 proportion group and low Mon2 proportion group according to the optimal cut-off value.There were significant differences in globu-lin,creatinine,fasting blood glucose,left ventricular end-systolic diameter,and Mon2 proportion between the two groups(P＜0.05).After adjusting for potential confounding factors using Cox re-gression,Mon2 proportion was found to be an important indicator for predicting poor prognosis after AMI.Kaplan-Meier survival analysis showed that the Mon2 proportion had a significant impact on the incidence of MACE in AMI patients with different risk stratifications.Conclusion Mon2 can improve the accuracy of predicting MACE after PCI,providing a new perspective for prognostic as-sessment in AMI patients.It is helpful for guiding clinical treatment decisions and improving patient prognosis.

Objective To investigate the molecular mechanism of miR-126-EPC-MPs in ameliorating oxygen glucose deprivation/reoxygenation (OGD/R) injury in cardiomyocytes.Methods The cardiomyocytes were used to establish the control and OGD/R injury models,and EPC-MPs and miR-126 mimic EPC-MPs treatments were administered respectively.The structural changes in cardiomyocyte organelles were assessed by transmission electron microscopy.ELISA was used to detect the expression levels of IL-6,TNF-α and HMGB-1 in cardiomyocytes.The protein and mRNA expression levels of Ang Ⅱ,caspase-6,eNOS,FOXO1,MPO,NF-κB,ERK1,LKB1,SIRT1,GRP78,GM130 and PGC-1α in cardiomyocytes after different treatments were detected by Western blot and quantitative PCR.Results The mitochondria structure in some cardiomyo-cytes of the OGD/R+miR-126 mimic EPC-MPs group was complete,the size of some mitochondria was in-creased,the surface of the endoplasmic reticulum had fewer ribosomes,and some of the Golgi vesicles gath-ered.Compared with the OGD/R+EPC-MPs group,the expression levels of IL-6,TNF-α and HMGB-1 in the OGD/R+miR-126 mimic EPC-MPs group were down-regulated.Compared with the OGD/R+EPC-MPs group,the expression levels of Ang Ⅱ,caspase-6,p-ERK1/2 and GRP78 protein in the OGD/R+miR-126 mimic EPC-MPs group were down-regulated,and the expression levels of p-LKB1,GM130 and PGC-1α protein in the OGD/R+miR-126 mimic EPC-MPs group were up-regulated.The quantitative PCR(qPCR) results showed that compared with the OGD/R+EPC-MPs group,the expression levels of Ang Ⅱ,MPO and GRP78 in the OGD/R+miR-126 mimic EPC-MPs group were down-regulated,and the expression levels of eNOS,GM130 and PGC-1α were up-regulated.Conclusion When OGD/R injury occurs in cardiomyocytes,miR-126 mimic EPC-MPs regulates PGC-1α/GM130 expression and inhibits Ang Ⅱ-induced stress injury response,thereby reduces the OGD/R damage in cardiomyocytes.