Objective To investigate the effects of endothelial progenitor cells(EPC)-derived microp-articles(MPs)with different injury treatments on EPC.Methods EPC cells were cultured and EPCs were i-dentified by flow cytometry.EPCs were treated with high glucose(HG)and tumor necrosis factor(TNF)-a recombinant protein,and MPs were extracted.The structural changes of microtubules,Golgi bodies and other organelles in EPC were observed by transmission electron microscopy.MTT assay was used to detect cell pro-liferation.Cell scratch assay was used to evaluate cell migration ability.Cell lumen formation assay was used to detect lumen formation.The expression levels of endothelial nitric oxide synthase(eNOS),silent informa-tion regulator 1(SIRT1),rat sarcoma(RAS)and extracellular regulated protein kinase(ERK)in EPC after different treatments were detected by quantitative real-time fluorescence PCR(qPCR)and Western blot.Re-sults Compared with the control-EPC-MPs group,the microtubule structure of the HG-EPC-MPs group and the TNF-α-EPC-MPs group was complete,the length was shortened,and the Golgi structure was relatively complete.Compared with the control-EPC-MPs group,the proliferation rate of EPC in the HG-EPC-MPs group and the TNF-α-EPC-MPs group was down-regulated,the cell migration ability was decreased,and the tube formation was decreased(P＜0.05).Compared with the control-EPC-MPs group,the mRNA and protein expressions of eNOS,SIRT1,RAS and ERK in the HG-EPC-MPs group and the TNF-α-EPC-MPs group were down-regula-ted(P＜0.05).Conclusion HG and TNF-α mediated MPs derived from EPC injury may change the structure of organelles in EPC by regulating the expression of SIRT1/ERK1 pathway proteins,thus affecting the biolog-ical function of EPC.

Objective To study the correlation between smoking and levels of endothelial microparticles(EMPs)in patients with acute myocardial infarction(AMI).Methods A total of 74 patients with AMI who were admittedto Xinjiang Uighur Autonomous Region People's Hospital from January 2020 to December 2020 were selected to be included in AMI group,and 72 patients with non-AMI chest tightness/pain were included in the non-AMI group.The general information of the patients in the two groups was collected,and the pe-ripheral venous bloodof the two groups was extracted.The EMPs levels and other clinical biochemical indexes were detected by flow cytometry.Results The proportion of males,WBC,proportion of smokers,and EMPslevel in patients in the AMI group were higher than those in the non-AMI group,and the difference was statistically significant(P＜0.05).The results of univariate logistic analysis showed that gender,WBC,EMPs,and smoking were risk factors for the development of AMI,and the difference was statistically signifi-cant(P＜0.05).Further multifactorial logistic regression results showed that high levels of elevated EMPs and smoking were independently associated with the occurrence of AMI.The receiver operating characteristic(ROC)curve was drawn to analyze the diagnostic value of EMPs in predicting AMI,and the area under the curve(AUC)between EMPs and AMI was 0.877(95％CI:0.824-0.929,P＜0.001).Logistic regression with EMPs as the dependent variable showed that low high-density lipoprotein(HDL)levels and smoking were independent risk factors for increased levels of EMPs.Conclusion High levels of EMPs and smoking were in-dependently associated with the development of AMI,and smoking-induced release of EMPs may be one of the reasons why patients are more likely to develop AMI.