Anti-HIV-1 Effect of Enoxacin by Modulation of Pro-viral hsa-miR-132 Processing

Background: Despite tremendous advances in antiretroviral therapy (ART) against HIV-1 infections no cure or vaccination is available. Therefore, discovering novel therapeutic strategies remains an urgent need. In that sense, miRNAs and miRNA therapeutics have moved intensively into the focus of recent HIV-1 related investigations. A strong reciprocal interdependence has been demonstrated between HIV-1 infection and changes of the intrinsic cellular miRNA milieu. This interrelationship may direct potential alterations of the host cells’ environment beneficial for the virus or its suppression of replication. Whether this tightly balanced and controlled battle can be exploited therapeutically, remains to be further addressed. In this context, the fluoroquinolone antibiotic Enoxacin has been demonstrated as a potent modulator of miRNA processing. Here, we test the hypothesis that this applies also to HIV-1 related miRNAs. Methods: We studied the effect of Enoxacin on HIV-1 replication coupled with miRNA qRT-PCR analysis of HIV-1 related miRNAs in CEM-SS and MT-4 T-cells. The effects of miRNA mimic transfections combined with Enoxacin treatment on HIV-1 replication were assessed. Finally, we employed an in vitro DICER1 cleavage assay to study the effects of Enoxacin on a pro-HIV-1 miRNA hsa-miR-132 processing. Results: We established that Enoxacin, but not the structurally similar compound nalidixic acid, exhibits strong anti-HIV-1 effects in the T-cell line CEM-SS, but not MT-4. We provide experimental evidence that this effect of Enoxacin is partly attributed to the specific downregulation of mature hsa-miR-132-3p, but not other pro- or anti-HIV-1 miRNAs, which is likely due to affecting DICER1 processing in a rather direct manner. Conclusions: Our findings show an anti-retroviral activity of Enoxacin via downregulation of hsa-miR-132-3p, which may be relevant for future antiviral therapeutic applications by modulation of the RNA interference pathway.

背景：尽管在抗逆转录病毒治疗（ART）对抗HIV-1感染方面取得了巨大的进展，但尚无治愈方法或疫苗可用。因此，发现新的治疗策略仍然是一项迫切的需求。在此意义上，miRNA及其治疗药物已迅速成为近期HIV-1相关研究的焦点。HIV-1感染与宿主细胞内源性miRNA微环境的改变之间存在着显著的相互依存关系。这种相互关系可能引导宿主细胞环境发生潜在的改变，有利于病毒的生长或抑制其复制。然而，这种紧密平衡且受控的斗争是否能够被用于治疗目的，尚需进一步探讨。在此背景下，氟喹诺酮类抗生素依诺沙星已被证实为miRNA加工的强效调节剂。本研究旨在验证这一作用同样适用于HIV-1相关的miRNA。方法：我们研究了依诺沙星对HIV-1复制的效应，并采用miRNA定量逆转录聚合酶链反应（qRT-PCR）分析了CEM-SS和MT-4 T细胞中HIV-1相关miRNA。评估了miRNA模拟转染与依诺沙星治疗联合对HIV-1复制的效应。最后，我们采用体外DICER1切割实验研究依诺沙星对促进HIV-1复制的miRNA hsa-miR-132加工的效应。结果：我们证实，与结构相似的化合物萘啶酸不同，依诺沙星在T细胞系CEM-SS中表现出显著的抗HIV-1活性，但在MT-4细胞中则不明显。我们提供了实验证据，表明依诺沙星的效果部分归因于成熟hsa-miR-132-3p的特异性下调，而不是其他促进或抑制HIV-1复制的miRNA，这可能是由于直接影响DICER1加工的结果。结论：我们的研究结果揭示了依诺沙星通过下调hsa-miR-132-3p展现的抗逆转录病毒活性，这可能与通过调节RNA干扰途径在未来抗病毒治疗应用中相关。