Department of Toxicology, School of Public Health, Lanzhou University, Lanzhou 730000, China.
Institute of Anthropotomy and Histoembryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
Toxicol Sci. 2022 Oct 27;190(1):64-78. doi: 10.1093/toxsci/kfac092.
Nickel oxide nanoparticles (Nano NiO) lead to pulmonary fibrosis, and the mechanisms are associated with epigenetics. This study aimed to clarify the regulatory relationship among long noncoding RNA HOXA transcript antisense RNA myeloid-specific 1 (HOTAIRM1), DNA methylation and expression of protein kinase C beta (PRKCB), and JNK/c-Jun pathway in Nano NiO-induced pulmonary fibrosis. Therefore, we constructed the rat pulmonary fibrosis model by intratracheal instillation of Nano NiO twice a week for 9 weeks and established the collagen deposition model by treating BEAS-2B cells with Nano NiO for 24 h. Here, the DNA methylation pattern was analyzed by whole-genome bisulfite sequencing in rat fibrotic lung tissues. Then, we integrated mRNA transcriptome data and found 93 DNA methylation genes with transcriptional significance. Meanwhile, the data showed that Nano NiO caused the down-regulation of lncRNA HOTAIRM1, the hypomethylation, and up-regulation of PRKCB2, JNK/c-Jun pathway activation, and collagen deposition (the up-regulated Col-I and α-SMA) both in vivo and in vitro. DNMTs inhibitor 5-AZDC attenuated Nano NiO-induced PRKCB2 expression, JNK/c-Jun pathway activation, and collagen deposition, but overexpression of PRKCB2 aggravated the changes mentioned indicators in Nano NiO-induced BEAS-2B cells. Furthermore, JNK/c-Jun pathway inhibitor (SP600125) alleviated Nano NiO-induced excessive collagen formation. Additionally, overexpression of HOTAIRM1 restrained the PRKCB hypomethylation, the activation of JNK/c-Jun pathway, and collagen formation induced by Nano NiO in BEAS-2B cells. In conclusion, these findings demonstrated that HOTAIRM1 could arrest Nano NiO-induced pulmonary fibrosis by suppressing the PRKCB DNA methylation-mediated JNK/c-Jun pathway.
氧化镍纳米颗粒（Nano NiO）可导致肺纤维化，其机制与表观遗传学有关。本研究旨在阐明长链非编码 RNA HOXA 转录物反义 RNA 髓系特异性 1（HOTAIRM1）、DNA 甲基化与蛋白激酶 Cβ（PRKCB）表达以及 JNK/c-Jun 通路之间的调控关系，在 Nano NiO 诱导的肺纤维化中。因此，我们通过每周两次气管内滴注 Nano NiO 构建大鼠肺纤维化模型，并用 Nano NiO 处理 BEAS-2B 细胞 24 h 构建胶原沉积模型。在此，通过大鼠纤维化肺组织的全基因组亚硫酸氢盐测序分析 DNA 甲基化模式。然后，我们整合了 mRNA 转录组数据，发现了 93 个具有转录意义的 DNA 甲基化基因。同时，数据显示 Nano NiO 导致 lncRNA HOTAIRM1 下调、PRKCB2 低甲基化和上调、JNK/c-Jun 通路激活以及胶原沉积（Col-I 和α-SMA 上调）在体内和体外均有发生。DNMTs 抑制剂 5-AZDC 减弱了 Nano NiO 诱导的 PRKCB2 表达、JNK/c-Jun 通路激活和胶原沉积，但 PRKCB2 的过表达加重了 Nano NiO 诱导的 BEAS-2B 细胞中提到的指标的变化。此外，JNK/c-Jun 通路抑制剂（SP600125）减轻了 Nano NiO 诱导的胶原过度形成。此外，HOTAIRM1 的过表达抑制了 Nano NiO 诱导的 BEAS-2B 细胞中 PRKCB 低甲基化、JNK/c-Jun 通路激活和胶原形成。总之，这些发现表明 HOTAIRM1 通过抑制 PRKCB DNA 甲基化介导的 JNK/c-Jun 通路来阻止 Nano NiO 诱导的肺纤维化。
