Department of Pharmaceutics, Daqing Campus of Harbin Medical University, Daqing 163319, China.
Department of Pharmaceutics, Harbin Medical University, Harbin 150086, China.
Biomaterials. 2014 Apr;35(11):3697-707. doi: 10.1016/j.biomaterials.2013.12.099. Epub 2014 Jan 24.
MicroRNA-1 (miR-1) has been found in cardiac and skeletal tissues. It is overexpressed in ischemic cardiac tissues. Down-regulation of miR-1 could relieve arrhythmogenesis by the anti-miR-1 antisense oligonucleotides (AMO-1). To increase the therapeutic efficiency and inhibit off-target effects of AMO-1, here we explored anti-cardiac troponin I (cTnI) antibody modified liposomes loading with AMO-1 (cT-A-LIP) to deliver the oligonucleotides to ischemic myocardium tissues. Liposomal cytotoxicity was assessed by MTT assay. The targeting abilities to foci were evaluated by in vivo imaging. The uptake and bio-distribution in vitro were observed by live cell station and flow cytometry, respectively. The anti-arrhythmic effects of cT-A-LIP in vivo were evaluated by electrocardiograms (ECG), immunohistochemistry, real-time PCR and patch-clamp recording. Immunohistochemistry showed that cTnI expression had a peak at the third day after myocardial infarction (MI). After cT-LIP administration via tail vein, accumulation of fluorescent trackers in the ischemic foci was significantly increased more than that of LIP. In addition, after cT-A-LIP administration, the ischemic arrhythmias were recovered and ST segment in ECG was elevated nearly back to normal. Compared with MI group, miR-1 expression was significantly down-regulated while Kir2.1 and CX43 protein expression were increased. Patch-clamp recordings showed that cT-A-LIP as well as AMO-1 incubation increased K(+) current density in guinea pigs ventricular cardiomyocytes acting on repolarized membrane potential. In conclusion, the cT-A-LIP not only delivered AMO-1 to ischemic myocardium in MI rats, but validated AMO-1 on relieving ischemic arrhythmia by silencing of miR-1 in ischemic myocardium and restoring the depolarized resting membrane potential (RMP) in MI rats.
miR-1 在心脏和骨骼组织中被发现。它在缺血性心脏组织中过度表达。通过抗 miR-1 反义寡核苷酸（AMO-1）下调 miR-1 可以缓解心律失常的发生。为了提高治疗效率并抑制 AMO-1 的脱靶效应，我们在此探索了载有 AMO-1 的抗心肌肌钙蛋白 I（cTnI）抗体修饰的脂质体（cT-A-LIP），以将寡核苷酸递送到缺血性心肌组织。通过 MTT 测定评估脂质体的细胞毒性。通过体内成像评估对病灶的靶向能力。通过活细胞工作站和流式细胞术分别观察体外摄取和生物分布。通过心电图（ECG）、免疫组织化学、实时 PCR 和膜片钳记录评估 cT-A-LIP 在体内的抗心律失常作用。免疫组织化学显示，心肌梗死（MI）后第三天 cTnI 表达达到峰值。尾静脉给予 cT-LIP 后，缺血病灶中荧光示踪剂的积累明显增加，超过了 LIP。此外，给予 cT-A-LIP 后，缺血性心律失常得到恢复，心电图中的 ST 段升高，几乎恢复正常。与 MI 组相比，miR-1 表达明显下调，而 Kir2.1 和 CX43 蛋白表达增加。膜片钳记录显示，cT-A-LIP 以及 AMO-1 孵育均增加了豚鼠心室肌细胞在去极化膜电位作用下的 K+电流密度。总之，cT-A-LIP 不仅将 AMO-1 递送到 MI 大鼠的缺血心肌中，而且通过在缺血心肌中沉默 miR-1 验证了 AMO-1 缓解缺血性心律失常并恢复 MI 大鼠去极化静息膜电位（RMP）。
