PDF(Pubmed)
Abstract：
The epigenetic regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), a pivotal redox transcription factor, plays a crucial role in maintaining cellular homeostasis. Recent research has underscored the significance of epigenetic modifications of Nrf2 in the pathogenesis of diabetic foot ulcers (DFUs). This study investigates the epigenetic reversal of Nrf2 by pterostilbene (PTS) in human endothelial cells in a hyperglycemic microenvironment (HGM). The activation potential of PTS on Nrf2 was evaluated through ARE-Luciferase reporter assays and nuclear translocation studies. Following 72 h of exposure to an HGM, mRNA expression and protein levels of Nrf2 and its downstream targets NAD(P)H quinone oxidoreductase 1 (NQO1), heme-oxygenase 1(HO-1), superoxide dismutase (SOD), and catalase (CAT) exhibited a decrease, which was mitigated in PTS-pretreated endothelial cells. Epigenetic markers, including histone deacetylases (HDACs class I-IV) and DNA methyltransferases (DNMTs 1/3A and 3B), were found to be downregulated under diabetic conditions. Specifically, Nrf2-associated HDACs, including HDAC1, HDAC2, HDAC3, and HDAC4, were upregulated in HGM-induced endothelial cells. This upregulation was reversed in PTS-pretreated cells, except for HDAC2, which exhibited elevated expression in endothelial cells treated with PTS in a hyperglycemic microenvironment. Additionally, PTS was observed to reverse the activity of the methyltransferase enzyme DNMT. Furthermore, CpG islands in the Nrf2 promoter were hypermethylated in cells exposed to an HGM, a phenomenon potentially counteracted by PTS pretreatment, as shown by methyl-sensitive restriction enzyme PCR (MSRE-qPCR) analysis. Collectively, our findings highlight the ability of PTS to epigenetically regulate Nrf2 expression under hyperglycemic conditions, suggesting its therapeutic potential in managing diabetic complications.
摘要：
核因子红系2相关因子2（Nrf2）的表观遗传调控，一个关键的氧化还原转录因子，在维持细胞稳态中起着至关重要的作用。最近的研究强调了Nrf2的表观遗传修饰在糖尿病足溃疡（DFU）发病机理中的重要性。这项研究调查了在高血糖微环境（HGM）中人类内皮细胞中，蝶芪（PTS）对Nrf2的表观遗传逆转。通过ARE-荧光素酶报告基因测定和核易位研究评估了PTS对Nrf2的激活潜力。暴露于HGM72小时后，Nrf2及其下游靶NAD(P)H醌氧化还原酶1(NQO1)的mRNA表达和蛋白水平,血红素加氧酶1（HO-1），超氧化物歧化酶（SOD），过氧化氢酶(CAT)表现出下降，在PTS预处理的内皮细胞中得到缓解。表观遗传标记,包括组蛋白脱乙酰酶（HDACsI-IV类）和DNA甲基转移酶（DNMTs1/3A和3B），被发现在糖尿病条件下下调。具体来说,Nrf2关联的HDAC，HDAC1、HDAC2、HDAC3和HDAC4在HGM诱导的内皮细胞中上调。这种上调在PTS预处理的细胞中被逆转，除了HDAC2，其在高血糖微环境中的PTS处理的内皮细胞中表现出升高的表达。此外,观察到PTS逆转甲基转移酶DNMT的活性。此外，Nrf2启动子中的CpG岛在暴露于HGM的细胞中高度甲基化，PTS预处理可能抵消的现象，如甲基敏感限制性内切酶PCR(MSRE-qPCR)分析所示。总的来说，我们的发现强调了PTS在高血糖条件下表观遗传调节Nrf2表达的能力，提示其治疗糖尿病并发症的潜力。
