DNA methylation is involved in pro-inflammatory cytokines expression in T-2 toxin-induced liver injury
DNA methylation is involved in pro-inflammatory cytokines expression in T-2 toxin-induced liver injury
复制标题
DNA 甲基化参与 T-2 毒素诱导的肝损伤中促炎细胞因子的表达
DOI：
10.1016/j.fct.2019.110661
复制
发表时间：
2019-10-01
影响因子：
4.3
通讯作者：
Yuan, Zonghui
中科院分区：
文献类型：
--
作者：
Liu, Aimei;Sun, Yaqi;Yuan, Zonghui
目前，T-2毒素已被报道可引起肝毒性，具有氧化应激和炎症作用;然而，T-2毒素诱导肝损伤的潜在机制尚未完全了解。越来越多的证据表明，DNA甲基化影响炎症细胞因子的表达，在自身免疫性疾病中起重要作用。然而，DNA甲基化在T-2毒素肝毒性中的潜在作用尚未被探索。在本研究中，雌性Wistar大鼠单次给予2 mg/kg b.w.的T-2毒素。并在暴露后1、3和7天处死。在体外，正常大鼠肝细胞系（BRL）暴露于不同浓度的T-2毒素。采用RT-PCR、Western blot、免疫组化、甲基化特异性PCR（MSP）、亚硫酸氢盐测序（BSP）、流式细胞术等方法，从分子水平检测肝脏损伤。结果表明，T-2毒素可显著提高肝细胞DNA甲基转移酶（DNMT 1、DNMT 3A）的水平，并主要集中在肝损伤部位。在T-2毒素处理的大鼠肝脏中，基因组DNA的5-甲基胞嘧啶（5-mC）水平也升高。在T-2毒素处理下，体内和体外炎性细胞因子（IL-6、IL-1 β、IL-11、IL-1 α和TNF-α）的表达均增加。值得注意的是，在T-2毒素暴露下，DNA去甲基化直接增加细胞因子IL-11、IL-6、IL-α和TNF-α的表达。DNA甲基化抑制剂与T-2毒素联合应用可直接或间接诱导炎性细胞因子的产生，加重细胞凋亡。我们的研究首次揭示了T-2毒素诱导的肝损伤中DNA甲基化与炎性细胞因子的表达有关。这些结果表明，DNA甲基化是T-2毒素诱导肝毒性的一个潜在机制。
Currently, T-2 toxin has been reported to cause liver toxicity with the effects of oxidative stress and inflammation; however, the underlying mechanism of T-2 toxin-induced liver injury is not fully understood. Increasing lines of evidence show that DNA methylation affects the expression of inflammatory cytokine, and plays a crucial role in autoimmune diseases. Nevertheless, the potential role of DNA methylation in the hepatotoxicity of T-2 toxin has not been explored. In this study, female Wistar rats were given a single dose of T-2 toxin at 2 mg/kg b.w. and were sacrificed at 1, 3 and 7 days post-exposure. In vitro, a normal rat liver cell line (BRL) was exposed to different concentrations of T-2 toxin. Histopathological analysis was used to investigate damage to the liver, which was detected at the molecular level by RT-PCR, Western blot and immunohistochemical assays, methylation-specific PCR (MSP), bisulfite sequencing (BSP), and flow cytometry. The results showed that T-2 toxin significantly increased the levels of DNA methyltransferases (DNMT1, DNMT3A), which were mainly concentrated at the site of liver injury. The 5-methylcytosine (5-mC) level of genomic DNA was also raised in T-2 toxin-treated rat livers. The expression of inflammatory cytokines (IL-6, IL-1 beta, IL-11, IL-1 alpha, and TNF-alpha) increased both in vivo and in vitro under T-2 toxin treatment. Notably, DNA demethylation directly increased the expression of cytokines IL-11, IL-6, IL-alpha, and TNF-alpha under T-2 toxin exposure. DNA methylation inhibitors combined with T-2 toxin directly or indirectly induced the production of inflammatory cytokines and aggravate cell apoptosis. Our study uncovered for the first time that DNA methylation is related to the expression of inflammatory cytokines in T-2 toxin-induced liver injury. These findings suggested that DNA methylation is a potential mechanism of T-2 toxin-induced hepatotoxicity.