Department of Radiation Oncology, The First Hospital of Jilin University, Changchun, China.
Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, China.
J Cell Mol Med. 2021 May;25(9):4408-4419. doi: 10.1111/jcmm.16504. Epub 2021 Apr 1.
Nuclear factor erythroid 2-related factor (Nrf2) is an important regulator of cellular antioxidant defence. We previously showed that SFN prevented Ang II-induced cardiac damage via activation of Nrf2. However, the underlying mechanism of SFN's persistent cardiac protection remains unclear. This study aimed to explore the potential of SFN in activating cardiac Nrf2 through epigenetic mechanisms. Wild-type mice were injected subcutaneously with Ang II, with or without SFN. Administration of chronic Ang II-induced cardiac inflammatory factor expression, oxidative damage, fibrosis and cardiac remodelling and dysfunction, all of which were effectively improved by SFN treatment, coupled with an up-regulation of Nrf2 and downstream genes. Bisulfite genome sequencing and chromatin immunoprecipitation (ChIP) were performed to detect the methylation level of the first 15 CpGs and histone H3 acetylation (Ac-H3) status in the Nrf2 promoter region, respectively. The results showed that SFN reduced Ang II-induced CpG hypermethylation and promoted Ac-H3 accumulation in the Nrf2 promoter region, accompanied by the inhibition of global DNMT and HDAC activity, and a decreased protein expression of key DNMT and HDAC enzymes. Taken together, SFN exerts its cardioprotective effect through epigenetic modification of Nrf2, which may partially contribute to long-term activation of cardiac Nrf2.
核因子红细胞 2 相关因子 2(Nrf2)是细胞抗氧化防御的重要调节因子。我们之前的研究表明,SFN 通过激活 Nrf2 来预防 Ang II 诱导的心脏损伤。然而,SFN 持续的心脏保护作用的潜在机制尚不清楚。本研究旨在探讨 SFN 通过表观遗传机制激活心脏 Nrf2 的潜力。野生型小鼠皮下注射 Ang II,同时或不给予 SFN。慢性 Ang II 诱导的心脏炎症因子表达、氧化损伤、纤维化和心脏重构及功能障碍,均被 SFN 治疗有效改善,同时 Nrf2 及其下游基因表达上调。进行亚硫酸氢盐基因组测序和染色质免疫沉淀(ChIP),分别检测 Nrf2 启动子区域的前 15 个 CpG 甲基化水平和组蛋白 H3 乙酰化(Ac-H3)状态。结果表明,SFN 降低了 Ang II 诱导的 CpG 过度甲基化,并促进了 Nrf2 启动子区域的 Ac-H3 积累,同时抑制了全局 DNA 甲基转移酶和组蛋白去乙酰化酶活性,关键的 DNA 甲基转移酶和组蛋白去乙酰化酶酶的蛋白表达降低。总之,SFN 通过 Nrf2 的表观遗传修饰发挥其心脏保护作用,这可能部分有助于心脏 Nrf2 的长期激活。