Urinary exosomal microRNA-145-5p and microRNA-27a-3p act as noninvasive diagnostic biomarkers for diabetic kidney disease

BACKGROUND Diabetic kidney disease(DKD),characterized by increased urinary microalbumin levels and decreased renal function,is the primary cause of end-stage renal di-sease.Its pathological mechanisms are complicated and multifactorial;Therefore,sensitive and specific biomarkers are needed.Urinary exosome originate from diverse renal cells in nephron segments and partially mirror the pathological changes in the kidney.The microRNAs(miRNAs)in urinary exosome are remark-ably stable and highly tissue-specific for the kidney.METHODS Type 2 diabetic mellitus(T2DM)patients were recruited from the Second Hospital of Hebei Medical University and were divided into two groups:DM,diabetic pa-tients without albuminuria[urinary albumin to creatinine ratio(UACR)<30 mg/g]and DKD,diabetic patients with albuminuria(UACR≥30 mg/g).Healthy subjects were the normal control(NC)group.Urinary exosomal miR-145-5p,miR-27a-3p,and miR-29c-3p,were detected using real-time quantitative polymerase chain reaction.The correlation between exosomal miRNAs and the clinical in-dexes was evaluated.The diagnostic values of exosomal miR-145-5p and miR-27a-3p in DKD were determined using receiver operating characteristic(ROC)analysis.Biological functions of miR-145-5p were investigated by performing RESULTS Urinary exosomal expression of miR-145-5p and miR-27a-3p was more upregulated in the DKD group than in the DM group(miR-145-5p:4.54±1.45 vs 1.95±0.93,P<0.001;miR-27a-3p:2.33±0.79 vs 1.71±0.76,P<0.05)and the NC group(miR-145-5p:4.54±1.45 vs 1.55±0.83,P<0.001;miR-27a-3p:2.33±0.79 vs 1.10±0.51,P<0.001).The exosomal miR-145-5p and miR-27a-3p positively correlated with albuminuria and serum creatinine and negatively correlated with the estimated glomerular filtration rate.miR-27a-3p was also closely related to blood glucose,gly-cosylated hemoglobin A1c,and low-density lipoprotein cholesterol.ROC analysis revealed that miR-145-5p had a better area under the curve of 0.88[95%confidence interval(CI):0.784-0.985,P<0.0001]in diagnosing DKD than miR-27a-3p with 0.71(95%CI:0.547-0.871,P=0.0239).Bioinformatics analysis revealed that the target genes of miR-145-5p were located in the actin filament,cytoskeleton,and extracellular exosome and were involved in the pathological processes of DKD,including apoptosis,inflammation,and fibrosis.CONCLUSION Urinary exosomal miR-145-5p and miR-27a-3p may serve as novel noninvasive diagnostic biomarkers or promising therapeutic targets for DKD.

Effect of pre-existing shear bands on mechanical properties and serration behaviors in bulk metallic glasses

Pre-existing（multiple）shear bands were introduced into the ductile Zr56Co28Al16 and Zr65Ni10Cu15Al10bulk metallic glasses（BMGs）through the lateral-deformation,respectively.It was found that the pre-exiting shear bands can further enhance the compressive plasticity of ductile BMGs.According to the serration analysis on the plastic deformation of the as-cast and the pre-deformed samples,the serration events in the stress-strain curves during deformation display a self-organized critical（SOC）behavior.Compared with the as-cast BMGs,a larger power-law scaling exponent calculated based on serrated flow behaviors becomes larger for the pre-deformed BMGs,implying that the shear banding stability of BMGs is effectively enhanced.This should be caused by the pronounced interactions of shear bands during plastic deformation for the pre-deformed BMGs.However,by introducing a large amount of multiple shear bands into the glassy matrix,it also becomes easier for shear bands to propagate along the pre-existing shear bands,leading to a lower cut-off elastic energy density for the pre-deformed BMGs.More multiple shear bands with stronger interactions for the pre-deformed BMGs could provide a larger chance to activate the shear-band cracking but less local elastic energies are remained for the subsequent crack-linking.