Department of Emergency Medicine, The Second People's Hospital of Yunnan Province, Kunming, 650021, Yunnan, PR China.
Department of Emergency, Wuding County People's Hospital, Chuxiong, 651600, Yunnan, PR China.
Exp Cell Res. 2020 Oct 15;395(2):112208. doi: 10.1016/j.yexcr.2020.112208. Epub 2020 Aug 3.
Forkhead box f1 (FoxF1), a transcription factor, was implicated in lung development. However, the molecular mechanism of FoxF1 in lung injury, specifically in injury caused by paraquat (PQ), one of the most frequently used herbicides, is unknown. Accordingly, we performed this study to investigate whether FoxF1 attenuates PQ-induced lung injury and to determine the possible mechanism.
We used PQ-treated Beas-2B cells to measure the expression of FoxF1. Later, ChIP-qPCR was applied to detect the levels of histone acetylation in cells, followed by the validation of the relationship between histone deacetylase-2 (HDAC2) and FoxF1. Subsequently, the correlation between FoxF1 and microRNA (miR)-342 and the downstream mechanism of miR-342 were evaluated by bioinformatics analysis. The apoptosis and the content of reactive oxygen species (ROS) in PQ-treated cells were detected to evaluate the roles of HDAC2, FoxF1 and miR-342 in vitro. Finally, a rat model was developed to evaluate the effects of HDAC2, miR-342 and Krüppel-like factor 5 (KLF5) on PQ-induced lung injury in vivo.
PQ treatment significantly enhanced FoxF1 promoter deacetylation, thereby inhibiting FoxF1 expression. After inhibition of HDAC2 activity, apoptosis and oxidative stress induced by PQ were significantly reversed. Nevertheless, further inhibition of miR-342 or overexpression of KLF5 promoted apoptosis and oxidative stress induced by PQ, and IκB/NF-κB p65 signaling was significantly activated after PQ treatment.
PQ treatment inhibited miR-342 expression by promoting HDAC2-induced deacetylation of the FoxF1 promoter, thereby promoting KLF5 expression and the IκB/NF-κB p65 signaling activation, and finally exacerbating PQ-induced lung injury in rats.
叉头框转录因子 F1（FoxF1）是一种转录因子，被认为与肺发育有关。然而，FoxF1 在肺损伤，特别是百草枯（PQ）引起的肺损伤中的分子机制尚不清楚。因此，我们进行了这项研究，以探讨 FoxF1 是否能减轻 PQ 诱导的肺损伤，并确定可能的机制。
我们使用 PQ 处理的 Beas-2B 细胞来测量 FoxF1 的表达。随后，应用染色质免疫沉淀定量 PCR（ChIP-qPCR）检测细胞中组蛋白乙酰化水平，验证组蛋白去乙酰化酶-2（HDAC2）与 FoxF1 之间的关系。然后，通过生物信息学分析评估 FoxF1 与 microRNA（miR）-342 之间的相关性及其下游机制。通过检测 PQ 处理细胞的凋亡和活性氧（ROS）含量，评估 HDAC2、FoxF1 和 miR-342 在体外的作用。最后，建立大鼠模型，评估 HDAC2、miR-342 和 Krüppel 样因子 5（KLF5）在体内对 PQ 诱导的肺损伤的影响。
PQ 处理显著增强了 FoxF1 启动子的去乙酰化，从而抑制了 FoxF1 的表达。抑制 HDAC2 活性后，PQ 诱导的细胞凋亡和氧化应激明显逆转。然而，进一步抑制 miR-342 或过表达 KLF5 促进了 PQ 诱导的细胞凋亡和氧化应激，并且 PQ 处理后 IκB/NF-κB p65 信号明显激活。
PQ 处理通过促进 FoxF1 启动子的 HDAC2 诱导去乙酰化，抑制 miR-342 的表达，从而促进 KLF5 的表达和 IκB/NF-κB p65 信号的激活，最终加重大鼠 PQ 诱导的肺损伤。
