A TRICk to Improve the Effectiveness of RIC: Role of Limb Temperature in Enhancing the Effectiveness of Remote Ischemic Conditioning

Biology

Claudia Penna¹  Pasquale Pagliaro¹  Francesca Tullio¹  Stefano Comit๠ Saveria Femminò²  Mara Brancaccio³  Matteo Sorge³ 

[1] Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy;Department of Medical Sciences, University of Turin, 10126 Turin, Italy;Department of Molecular Biotechnology and Health Sciences, University of Turin, 10126 Turin, Italy;

关键词: cardioprotection;    remote ischemic conditioning;    infarct size;    reperfusion injury;   

DOI  :  10.3390/biology11010146

来源: DOAJ

【 摘 要 】

Background: Treatment of myocardial ischemia/reperfusion (IR) injury is still an unmet clinical need. A large variability of remote ischemic conditioning (RIC) protection has been reported; however, no studies have considered the temperature of the ischemic limb. We analyzed the effects of temperature on RIC protection. Methods: Left hind-limbs of anesthetized male mice were immersed in warm (40 °C, warm-RIC) or cold (20 °C, cold-RIC) water and subjected to a RIC protocol (4 × 5 min limb ischemia/reperfusion). In the control groups (warm-CTR or cold-CTR), the limbs underwent thermic conditions only. Isolated hearts underwent 30 min ischemia and 60 min reperfusion. A PI3K-inhibitor, LY294002 (5 µM), was infused in warm-RIC hearts before the IR protocol (warm-RIC LY). Infarct size was evaluated by nitro blue tetrazolium staining and expressed as the percent of risk area. Results: While cold-RIC did not reduce the infarct size compared to cold-CTR (51 ± 1.62% vs. 54 ± 1.07% of risk area, p = NS), warm-RIC (44 ± 1.13%) significantly reduced the infarct size with respect to either cold-RIC (p < 0.001) or warm-CTR (58 ± 1.41%, p < 0.0001). LY294002 infusion revealed the PI3K/Akt involvement in the warm-RIC protection. Infarct size reduction was abrogated by LY294002 pretreatment (warm-RIC: 44 ± 1.13% vs. warm-CTR 58 ± 1.41% p < 0.0001; vs. warm-RIC LY 54 ± 1.69% p = 0.0002). Conclusion: our study shows a remarkable difference between warm-RIC and cold-RIC in terms of infarct size reduction, supporting a pivotal role for limb temperature in RIC-induced cardioprotection.

【 授权许可】

Unknown