State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin, China.
Biomaterials. 2017 Jun;130:14-27. doi: 10.1016/j.biomaterials.2017.03.027. Epub 2017 Mar 22.
The biosafety and biological effects of silver nanoparticles (AgNPs) on human health attract increasing concern. Although considerable studies have been performed to reveal the molecular mechanisms responsible for AgNP-induced effects, the current understanding mainly focuses on oxidative stress-associated signaling pathways activated by Ag particles and/or Ag ions. However, the molecular bases underlying the activation of these stress signaling pathways have not been thoroughly elucidated yet. In the current study, we aimed to shed light on the molecular bases of AgNP-induced effects on erythroid cells from the perspective of long noncoding RNAs. We identified a long-noncoding RNA molecule, ODRUL, which was substantially enhanced in K562 erythroid cells responding to AgNPs, coupled to accelerated cell death. Further, we uncovered oxidative stress-driven Nrf2 transcriptionally promoted ODRUL expression in K562 cells. Downstream of Nrf2-ODRUL activation by AgNPs, ODRUL was recognized to interact with PI4Kα protein to modulate the activities of its targets AKT and JNK. As a result, the Bcl-2 level was negatively regulated by PI4K-AKT/JNK signaling under AgNP-induced stress, leading to enhanced cell death. Together, our findings unearthed that Nrf2-mediated lncRNA ODRUL was indispensable for AgNP-induced toxicity in erythroid cells through regulation of AKT/JNK-Bcl-2 signaling dependent on a physical interaction with PI4Kα. Thus, this study would open a new path to depict the molecular bases of AgNP-induced effects on erythroid cells.
银纳米粒子(AgNPs)的生物安全性和生物学效应对人类健康的影响引起了越来越多的关注。尽管已经进行了相当多的研究来揭示导致 AgNP 诱导效应的分子机制,但目前的认识主要集中在 Ag 颗粒和/或 Ag 离子激活的与氧化应激相关的信号通路。然而,这些应激信号通路被激活的分子基础尚未得到彻底阐明。在本研究中,我们旨在从长非编码 RNA 的角度阐明 AgNP 诱导的红细胞效应的分子基础。我们鉴定了一种长非编码 RNA 分子 ODRUL,它在响应 AgNPs 的 K562 红细胞中显著增强,与加速细胞死亡有关。此外,我们揭示了氧化应激驱动的 Nrf2 转录促进 K562 细胞中 ODRUL 的表达。在 AgNPs 激活 Nrf2-ODRUL 之后,发现 ODRUL 与 PI4Kα 蛋白相互作用,调节其靶标 AKT 和 JNK 的活性。结果,PI4K-AKT/JNK 信号下调 Bcl-2 水平,导致 AgNP 诱导应激下细胞死亡增强。总之,我们的研究结果表明,Nrf2 介导的长非编码 RNA ODRUL 通过与 PI4Kα 的物理相互作用调节 AKT/JNK-Bcl-2 信号,对于红细胞中 AgNP 诱导的毒性是必不可少的。因此,本研究将为描绘 AgNP 诱导的红细胞效应的分子基础开辟新的途径。