Abstract 14314: miR-210 Modulates Tissue Response to Hindlimb Ischemia and the Ensuing Regeneration
Background: MicroRNA-210 (miR-210) is a key player of endothelial cell response to hypoxia, modulating glycolysis, VEGF-driven endothelial cell migration and the ability of endothelial cells to form capillary-like structures in vitro. However, its in vivo role is poorly characterized. The aim of this study is understanding miR-210 regulation and role in a mouse model of hindlimb ischemia.
Methods and Results: miR-210 expression in the gastrocnemius muscle increased 3±0.5 fold at 3 days after femoral artery dissection (n=7; p<0.004). miR-210 levels remained high at day 7 and declined afterwards. To investigate miR-210 role in tissue response to ischemia, its function was inhibited by tail vein injection of LNA-anti-miR-210. In both liver and skeletal muscle, LNA-anti-miR-210 caused a 4 fold decrease of miR-210 compared to LNA-scramble control, while miR-210 targets CPEB2 and DDAH1 increased accordingly. Histological evaluation of acute tissue damage showed that LNA-anti-miR-210 treatment increased >4 fold both apoptosis at 1 day and necrosis at 3 days, compared to control (n=4; p<0.002). Damage/necrosis areas were similar at later timepoints, indicating that miR-210 depletion accelerated ischemic damage onset that eventually affected control mice as well. The pro-survival role of miR-210 was confirmed by in vitro experiments showing that miR-210 blockade more than doubled apoptosis in endothelial cells exposed to 1% O2 (p<0.01; n=3). When regeneration was evaluated, LNA-anti-miR-210 treated mice displayed 3.6±0.9 fold more regenerating myofibers at 7 days after femoral artery dissection (n=4; p<0.002). In agreement with this observation, we found that miR-210 blockade facilitated the differentiation of C2C12 myoblasts in vitro, as assessed measuring the expression of “classical” differentiation markers (MHC, desmin) and of myo-miRNAs (miR-1, -133a-133b, -206).
Conclusions: miR-210 plays an integral role in the mechanisms underpinning tissue response to ischemia.
- © 2010 by American Heart Association, Inc.