Pandey Raghav, Velasquez Sebastian, Durrani Shazia, Jiang Min, Neiman Michelle, Crocker Jeffrey S, Benoit Joshua B, Rubinstein Jack, Paul Arghya, Ahmed Rafeeq Ph
Department of Pathology and Laboratory Medicine, College of Medicine, University of CincinnatiCincinnati 45267, OH, USA.
Department of Internal Medicine, Division of Cardiovascular Diseases, College of Medicine, University of CincinnatiCincinnati 45267, OH, USA.
Am J Transl Res. 2017 Jun 15;9(6):3120-3137. eCollection 2017.
In mammals, proliferative capacity of cardiomyocytes is lost soon after birth, while zebrafish and other lower organisms like newts are known to regenerate injured hearts even at an adult age. Here, we show that miR-1825 can induce robust proliferation of adult rat cardiomyocytes and can improve cardiac function in-vivo post myocardial infarction. Rat adult cardiomyocytes transfected with miR-1825 showed a significant increase in DNA synthesis, mitosis, cytokinesis, and an increase in cell number when compared to cel-miR-67 transfected control. We also observed a reduction in mitochondrial number and a decrease in ROS and DNA-damage. RNA-sequencing data identified NDUFA10, a key gene involved in the mitochondrial electron transport chain to be a direct target of miR-1825. SiRNA mediated silencing of NDUFA10 showed a significant increase in cardiomyocyte proliferation indicating its role downstream of miRNA-1825. In addition, microRNA microarray results identified miR-1825 to regulate expression of a known proliferation inducing miRNA, miR-199a. We also identified the direct targets of miR-199a, namely p16, Rb1, and Meis2 to be downregulated following miR-1825 transfection. However, miR-199a alone did not have similar proliferation inducing effects as miR-1825, indicating that miR-1825 works through multiple pathways and is a master regulator of cardiomyocyte proliferation. In addition, our in-vivo analysis in animal models of LAD ligation and intra-cardiac miRNA delivery showed proliferation of endogenous cardiomyocytes in the peri-infarcted region and an improvement in heart function. These findings establish miR-1825 as a potential therapeutic agent for induction of cardiomyocyte proliferation and cardiac regeneration, with a significant translational potential.
在哺乳动物中，心肌细胞的增殖能力在出生后不久就会丧失，而斑马鱼和蝾螈等其他低等生物即使在成年后也能再生受损心脏。在此，我们表明miR-1825可诱导成年大鼠心肌细胞强劲增殖，并可在心肌梗死后改善体内心脏功能。与转染cel-miR-67的对照组相比，用miR-1825转染的成年大鼠心肌细胞在DNA合成、有丝分裂、胞质分裂方面显著增加，细胞数量也增加。我们还观察到线粒体数量减少，活性氧和DNA损伤减少。RNA测序数据确定参与线粒体电子传递链的关键基因NDUFA10是miR-1825的直接靶点。小干扰RNA介导的NDUFA10沉默显示心肌细胞增殖显著增加，表明其在miRNA-1825下游发挥作用。此外，微小RNA微阵列结果确定miR-1825可调节已知的增殖诱导微小RNA miR-199a的表达。我们还确定miR-199a的直接靶点，即p16、Rb1和Meis2在miR-1825转染后下调。然而，单独的miR-199a没有与miR-1825类似的增殖诱导作用，表明miR-1825通过多种途径发挥作用，是心肌细胞增殖的主要调节因子。此外，我们在左前降支结扎和心脏内微小RNA递送的动物模型中的体内分析显示，梗死周边区域的内源性心肌细胞增殖，心脏功能改善。这些发现确立了miR-1825作为诱导心肌细胞增殖和心脏再生的潜在治疗剂，具有显著的转化潜力。
