Xenon (Xe) preconditioning up-regulated miR-21 and knockdown of miR-21 exacerbated renal ischemia-reperfusion (IR) injury following xenon exposure. (A) Xenon significantly increased miR-21 expression 24 h after IR injury following xenon preconditioning. *P < 0.05 versus IR group, n = 5. (B) Xenon significantly increased miR-21 expression from 2 h after exposure compared with N2 control. *P < 0.05 versus control, n = 5 at each time point. (C) Locked nucleic acid anti–miR-21 (10 mg/kg), administered before xenon preconditioning inhibited miR-21 expression effectively in kidneys 24 h after xenon exposure. *P < 0.05 versus Xe + scramble, n = 5. (D) Locked nucleic acid anti–miR-21 administered before xenon preconditioning, inhibited miR-21 expression effectively in kidneys 24 h after IR injury. *P < 0.05 versus Xe + scramble + IR, n = 5. (E) Knockdown of miR-21 in mice exposed to xenon significantly increased serum creatinine at 24 and 48 h after IR injury. *P < 0.05 versus Xe + scramble + IR group, n = 5 at each time point. (F and G) Tubular cell injury and quantification of histologic scoring 24 h after IR injury in mice receiving anti–miR-21 or scrambled anti-miR. *P < 0.05 versus Xe + scramble + IR group, n = 6. Data are means ± SD. N2 = nitrogen.
