Upregulation of microRNA-451a improves endothelial cell function in atherosclerosis by direct targeting of macrophage migration inhibitory factor

This study aims to detect the expression of selected circulating microRNAs(miRNA),including miRNA-451a,miRNA-486-5p and miR-10b-5p,and their prospective roles as biomarkers in patients with atherosclerosis.For this purpose,levels of miRNAs were detected by real-time quantitative polymerase chain reaction(RT-qPCR)in case(N=30)and healthy control(N=30)groups.Receiver operating characteristic(ROC)curve analysis was carried out to evaluate the diagnostic ability of miRNAs.The correlations of miR-451a with lipid parameters were evaluated using Pearson’s correlation coefficients.HUVEC tested by ox-LDL was used as a cellular model of atherosclerosis.Cell viability and apoptosis were detected by methyl thiazolyl tetrazolium(MTT)and flow cytometry(FC)assays.Luciferase assay was used to determine the miRNA binding site on target genes.The results showed that miRNA-451a expression level was significantly lower in patients than controls.ROC curve analysis showed that the areas under the curve(AUC)of plasma miRNA-451a was 0.90.The miRNA-451a expression level exhibited significant negative correlations with cholesterol(TC),triglyceride(TG),and low-density lipoprotein(LDL).Besides,miRNA-451a specifically binds to the 3’UTR of macrophage migration inhibitory factor(MIF)and mediated the cell proliferation and apoptosis of HUVECs exposed to ox-LDL.Furthermore,overexpression of miRNA-451a promoted the proliferation and alleviated apoptosis of HUVECs exposed to ox-LDL,while this result was attenuated by macrophage migration inhibitory factor(MIF)overexpression.Therefore,miRNA-451a could be considered as a potential biomarker for atherosclerosis and miRNA-451a might contribute to regulating atherosclerosis through targeting MIF.

Continued antigenic variation of highly pathogenic avian influenza A(H7N9)virus in laying hens in China,2020–2021

Dear Editor,Since it first appeared in humans in China in 2013,a novel H7N9influenza virus has caused 1,568 cases of infection,with a mortality rate of 39.2%(Yin et al.,2021).The early H7N9 virus strains had low pathogenicity and did not cause avian disease(Zhang et al.,2013).However,they caused concern about poultry consumption and caused huge economic losses to the poultry industry.Since mid-2016,some H7N9 viruses mutated.