hWJMSC-MVs observed by transmission electron microscopy and effects in IRI induced AKI in rats. (A) hWJMSC-MVs were heterogeneous lipid bi-layer vesicles that range from 30 to 500 nm in diameter, and were characterized by cup-shaped morphology (Scale bar = 1 um). (B) Representative micrographs of renal histology at 48 h after reperfusion, in sham-operated rats and in MVs rats or vehicle (Original magnification 200×. Scale bar = 50 um). (C) Histopathological scoring shows a significant difference between the MV-treated group and vehicle, sham versus vehicle group, MVs versus sham group (n = 6. *P <0.05, sham versus vehicle, #P <0.05, MVs versus vehicle, **P <0.05, sham versus MVs). (D) vWF in plasma was increased at 24 h and 48 h, respectively, after IRI. However, in the MVs group, there is a significantly decreased vWF level in 24 h and 48 h compared with the vehicle group. All quantitative data are shown as mean ± SD of six serum samples for each experimental condition. (n = 6. *P <0.05, sham versus vehicle; #P <0.05, MVs versus vehicle, **P <0.05, sham versus MVs). AKI, acute kidney injury; hWJMSC, human Wharton-Jelly mesenchymal stem cells; IRI, ischemia/reperfusion injury; MVs, microvesicles.