Bartman Colleen Marie, Oyama Yoshimasa, Brodsky Kelley, Khailova Ludmila, Walker Lori, Koeppen Michael, Eckle Tobias
Department of Anesthesiology, University of Colorado Denver School of Medicine, Aurora, CO, United States of America.
Department of Cell and Developmental Biology, University of Colorado Denver School of Medicine, Aurora, CO, United States of America.
PLoS One. 2017 Apr 27;12(4):e0176243. doi: 10.1371/journal.pone.0176243. eCollection 2017.
A wide search for ischemic preconditioning (IPC) mechanisms of cardioprotection identified the light elicited circadian rhythm protein Period 2 (Per2) to be cardioprotective. Studies on cardiac metabolism found a key role for light elicited Per2 in mediating metabolic dependence on carbohydrate metabolism. To profile Per2 mediated pathways following IPC of the mouse heart, we performed a genome array and identified 352 abundantly expressed and well-characterized Per2 dependent micro RNAs. One prominent result of our in silico analysis for cardiac Per2 dependent micro RNAs revealed a selective role for miR-21 in the regulation of hypoxia and metabolic pathways. Based on this Per2 dependency, we subsequently found a diurnal expression pattern for miR-21 with higher miR-21 expression levels at Zeitgeber time (ZT) 15 compared to ZT3. Gain or loss of function studies for miR-21 using miRNA mimics or miRNA inhibitors and a Seahorse Bioanalyzer uncovered a critical role of miR-21 for cellular glycolysis, glycolytic capacity, and glycolytic reserve. Exposing mice to intense light, a strategy to induce Per2, led to a robust induction of cardiac miR-21 tissue levels and decreased infarct sizes, which was abolished in miR-21-/- mice. Similarly, first translational studies in humans using intense blue light exposure for 5 days in healthy volunteers resulted in increased plasma miR-21 levels which was associated with increased phosphofructokinase activity, the rate-limiting enzyme in glycolysis. Together, we identified miR-21 as cardioprotective downstream target of Per2 and suggest intense light therapy as a potential strategy to enhance miR-21 activity and subsequent carbohydrate metabolism in humans.
对心脏保护的缺血预处理（IPC）机制进行的广泛研究发现，光诱导的昼夜节律蛋白Period 2（Per2）具有心脏保护作用。对心脏代谢的研究发现，光诱导的Per2在介导对碳水化合物代谢的代谢依赖性方面起着关键作用。为了分析小鼠心脏IPC后Per2介导的信号通路，我们进行了基因芯片分析，鉴定出352个大量表达且特征明确的Per2依赖性微小RNA。我们对心脏Per2依赖性微小RNA进行的计算机分析的一个突出结果显示，miR-21在缺氧和代谢信号通路的调节中具有选择性作用。基于这种对Per2的依赖性，我们随后发现miR-21具有昼夜表达模式，与Zeitgeber时间（ZT）3相比，在ZT15时miR-21表达水平更高。使用miRNA模拟物或miRNA抑制剂对miR-21进行功能获得或缺失研究，并结合海马生物分析仪，揭示了miR-21对细胞糖酵解、糖酵解能力和糖酵解储备的关键作用。将小鼠暴露于强光下（一种诱导Per2的策略），导致心脏miR-21组织水平显著升高，梗死面积减小，而在miR-21基因敲除小鼠中这种现象消失。同样，在健康志愿者中进行的首次人体转化研究中，使用强蓝光照射5天，导致血浆miR-21水平升高，这与糖酵解限速酶磷酸果糖激酶活性增加有关。总之，我们确定miR-21是Per2的心脏保护下游靶点，并提出强光疗法作为增强人类miR-21活性及后续碳水化合物代谢的潜在策略。
