Fig. 4

Kidney injury score and DNA-damaged marker by day 5 after SS-AKIR procedure. A–F Light microscopic findings (200x; H&E stain) showing significantly higher loss of brush border in renal tubules (yellow arrows), tubular necrosis (green arrows), tubular dilatation (red asterisk), protein cast formation (black asterisk), and dilatation of Bowman’s capsule (blue arrows) in IR group than in other groups. Scale bars in right lower corner represent 50 µm. H–M Illustrating the immunofluorescent (IF) microscopic finding (400x) for identification of γ-H2AX + cells (red color). N Analytical result of number of γ-H2AX + cells. Scale bars in right lower corner represent 20 µm. n = 6 for each group. * indicates p value  < 0.05; ** indicates p value  < 0.01; *** indicates p value  < 0.001; **** indicates p value  < 0.0001. G1 = (sham-operated control); G2 = sepsis syndrome (SS) + acute kidney ischemia–reperfusion (AKIR); G3 (SS + AKIR + ciprofloxacin administered at 3 h after SS-AKIR induction); G4 [SS + AKIR + iPS-MSCs by intravenous injection at 3 h, after SS-AKIR (i.e., defined as early treatment)]; G5 [SS + AKIR + iPS-MSCs by intravenous injection at 18 h after SS-AKIR (i.e., defined as late treatment) after SS-AKIR induction]; G6 [SS + AKIR + ciprofloxacin and iPS-MSCs at 3 h after SS-AKIR induction]. iPS-MSCs = induced pluripotent stem cells-derived mesenchymal stem cells