From the Molecular Medicine (P.L., G.P., V.M., M.G.) and Cardiovascular Biology (S.Z.) Laboratories, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy; and Department of Medical, Surgical and Health Sciences, University of Trieste, Italy (P.L., G.S., S.Z., M.G.).
Circ Res. 2017 Apr 14;120(8):1298-1304. doi: 10.1161/CIRCRESAHA.116.309589. Epub 2017 Jan 11.
Recent evidence indicates that a few human microRNAs (miRNAs), in particular hsa-miR-199a-3p and hsa-miR-590-3p, stimulate proliferation of cardiomyocytes and, once expressed in the mouse heart using viral vectors, induce cardiac regeneration after myocardial infarction. Viral vectors, however, are not devoid of safety issues and, more notably, drive expression of the encoded miRNAs for indefinite periods of time, which might not be desirable in light of human therapeutic application.
As an alternative to the use of viral vectors, we wanted to assess the efficacy of synthetic miRNA mimics in inducing myocardial repair after single intracardiac injection using synthetic lipid formulations.
We comparatively analyzed the efficacy of different lipid formulations in delivering hsa-miR-199a-3p and hsa-miR-590-3p both in primary neonatal mouse cardiomyocytes and in vivo. We established a transfection protocol allowing persistence of these 2 mimics for at least 12 days after a single intracardiac injection, with minimal dispersion to other organs and long-term preservation of miRNA functional activity, as assessed by monitoring the expression of 2 mRNA targets. Administration of this synthetic formulation immediately after myocardial infarction in mice resulted in marked reduction of infarct size and persistent recovery of cardiac function.
A single administration of synthetic miRNA-lipid formulations is sufficient to stimulate cardiac repair and restoration of cardiac function.
最近的证据表明，少数人类 microRNAs（miRNAs），特别是 hsa-miR-199a-3p 和 hsa-miR-590-3p，能够刺激心肌细胞增殖，并且使用病毒载体在小鼠心脏中表达后，能够在心肌梗死后诱导心脏再生。然而，病毒载体并非没有安全问题，更值得注意的是，它们会在很长一段时间内驱动编码 miRNA 的表达，这在考虑到人类治疗应用时可能并不理想。
作为使用病毒载体的替代方法，我们希望评估使用合成脂质制剂通过单次心内注射合成 miRNA 模拟物在诱导心肌修复方面的功效。
我们比较分析了不同脂质制剂在体外原代培养的新生小鼠心肌细胞和体内递送 hsa-miR-199a-3p 和 hsa-miR-590-3p 的功效。我们建立了一种转染方案，允许这 2 种模拟物在单次心内注射后至少持续 12 天，同时最小程度地分散到其他器官，并通过监测 2 个 mRNA 靶标表达来长期保持 miRNA 功能活性。在小鼠心肌梗死后立即给予这种合成制剂可显著减少梗死面积，并持续恢复心脏功能。
单次给予合成 miRNA-脂质制剂足以刺激心脏修复和心脏功能的恢复。
