[HTML][HTML] Delayed ischemic preconditioning contributes to renal protection by upregulation of miR-21

X Xu, AJ Kriegel, Y Liu, K Usa, D Mladinov, H Liu… - Kidney international, 2012 - Elsevier
X Xu, AJ Kriegel, Y Liu, K Usa, D Mladinov, H Liu, Y Fang, X Ding, M Liang
Kidney international, 2012Elsevier
Delayed ischemic preconditioning effectively protects kidneys from ischemia–reperfusion
injury but the mechanism underlying renal protection remains poorly understood. Here we
examined the in vivo role of microRNA miR-21 in the renal protection conferred by delayed
ischemic preconditioning in mice. A 15-min renal ischemic preconditioning significantly
increased the expression of miR-21 by 4 h and substantially attenuated ischemia–
reperfusion injury induced 4 days later. A locked nucleic acid–modified anti-miR-21 given at …
Delayed ischemic preconditioning effectively protects kidneys from ischemia–reperfusion injury but the mechanism underlying renal protection remains poorly understood. Here we examined the in vivo role of microRNA miR-21 in the renal protection conferred by delayed ischemic preconditioning in mice. A 15-min renal ischemic preconditioning significantly increased the expression of miR-21 by 4 h and substantially attenuated ischemia–reperfusion injury induced 4 days later. A locked nucleic acid–modified anti-miR-21 given at the time of ischemic preconditioning knocked down miR-21 and significantly exacerbated subsequent ischemia–reperfusion injury in the mouse kidney. Knockdown of miR-21 resulted in significant upregulation of programmed cell death protein 4, a proapoptotic target gene of miR-21, and substantially increased tubular cell apoptosis. Hypoxia-inducible factor-1α in the kidney was activated after ischemic preconditioning and blockade of its activity with a decoy abolished the upregulation of miR-21 in cultured human renal epithelial cells treated with the inducer cobalt chloride. In the absence of ischemic preconditioning, knockdown of miR-21 alone did not significantly affect ischemia–reperfusion injury in the mouse kidney. Thus, upregulation of miR-21 contributes to the protective effect of delayed ischemic preconditioning against subsequent renal ischemia–reperfusion injury.
Elsevier