b-pEPCs improved IR-induced vascular injury and fibrosis by regulating PDGFR-β-positive pericytes. A. Immunofluorescence staining of PDGFR-β and CD31 to locate pericytes and endothelial cells; white triangles reveal the gap between pericytes and endothelial cells in the IR+EBM-2 group, white arrows represent pericytes attached to and located surrounding endothelial cells. The ratio of PDGFR-β/CD31 represents vascular structure stability and balance. In the normal kidney, PDGFR-β/CD31 is less than 0.4. The increased ratio implies abnormal and unstable vascular structures. B and C. Western blot and qRT-PCR to test PDGFR-β at protein and RNA levels. D. Co-staining of PCNA and PDGFR-β (orange arrows) to measure the number of proliferative pericytes. E. Co-staining of α-SMA and PDGFR-β to measure pericyte-derived myofibroblasts. The ratio of the α-SMA+PDGFR-β+/α-SMA+ area shows the portion of pericyte-derived myofibroblasts. Data are presented as the mean ± SD, n=3-5/group, *p<0.05, **p<0.01. Scale bar: 50 μm.