萝卜硫素重编中央代谢以支持抗氧化反应并实现葡萄糖内稳态。
Sulforaphane rewires central metabolism to support antioxidant response and achieve glucose homeostasis.
机构信息
Quadram Institute Bioscience, Norwich Research Park, Norwich, United Kingdom.
Braunschweig Integrated Centre of System Biology, Technical University of Braunschweig, Braunschweig, Germany.
出版信息
Redox Biol. 2023 Nov;67:102878. doi: 10.1016/j.redox.2023.102878. Epub 2023 Sep 7.
Cruciferous-rich diets, particularly broccoli, have been associated with reduced risk of developing cancers of various sites, cardiovascular disease and type-2 diabetes. Sulforaphane (SF), a sulfur-containing broccoli-derived metabolite, has been identified as the major bioactive compound mediating these health benefits. Sulforaphane is a potent dietary activator of the transcription factor Nuclear factor erythroid-like 2 (NRF2), the master regulator of antioxidant cell capacity responsible for inducing cytoprotective genes, but its role in glucose homeostasis remains unclear. In this study, we set to test the hypothesis that SF regulates glucose metabolism and ameliorates glucose overload and its resulting oxidative stress by inducing NRF2 in human hepatoma HepG2 cells. HepG2 cells were exposed to varying glucose concentrations: basal (5.5 mM) and high glucose (25 mM), in the presence of physiological concentrations of SF (10 μM). SF upregulated the expression of glutathione (GSH) biosynthetic genes and significantly increased levels of reduced GSH. Labelled glucose and glutamine experiments to measure metabolic fluxes identified that SF increased intracellular utilisation of glycine and glutamate by redirecting the latter away from the TCA cycle and increased the import of cysteine from the media, likely to support glutathione synthesis. Furthermore, SF altered pathways generating NADPH, the necessary cofactor for oxidoreductase reactions, namely pentose phosphate pathway and 1C-metabolism, leading to the redirection of glucose away from glycolysis and towards PPP and of methionine towards methylation substrates. Finally, transcriptomic and targeted metabolomics LC-MS analysis of NRF2-KD HepG2 cells generated using CRISPR-Cas9 genome editing revealed that the above metabolic effects are mediated through NRF2. These results suggest that the antioxidant properties of cruciferous diets are intricately connected to their metabolic benefits.
十字花科蔬菜丰富的饮食,特别是西兰花,与降低各种部位癌症、心血管疾病和 2 型糖尿病的风险有关。萝卜硫素(SF),一种含硫的西兰花衍生代谢物,已被确定为介导这些健康益处的主要生物活性化合物。萝卜硫素是转录因子核因子红细胞样 2(NRF2)的一种有效的膳食激活剂,NRF2 是抗氧化细胞能力的主要调节因子,负责诱导细胞保护基因,但它在葡萄糖稳态中的作用尚不清楚。在这项研究中,我们假设 SF 通过在人肝癌 HepG2 细胞中诱导 NRF2 来调节葡萄糖代谢并改善葡萄糖过载及其导致的氧化应激。HepG2 细胞暴露于不同的葡萄糖浓度:基础(5.5 mM)和高葡萄糖(25 mM),同时存在生理浓度的 SF(10 μM)。SF 上调了谷胱甘肽(GSH)生物合成基因的表达,并显著增加了还原型 GSH 的水平。测量代谢通量的标记葡萄糖和谷氨酰胺实验表明,SF 通过将后者从 TCA 循环中转移出来,增加了细胞内甘氨酸和谷氨酸的利用,并增加了胱氨酸从培养基中的输入,可能支持谷胱甘肽的合成。此外,SF 改变了生成 NADPH 的途径,NADPH 是氧化还原酶反应的必要辅助因子,即戊糖磷酸途径和 1C 代谢,导致葡萄糖从糖酵解转向 PPP,以及甲硫氨酸转向甲基化底物的方向。最后,使用 CRISPR-Cas9 基因组编辑生成的 NRF2-KD HepG2 细胞的转录组和靶向代谢组学 LC-MS 分析表明,上述代谢效应是通过 NRF2 介导的。这些结果表明,十字花科蔬菜饮食的抗氧化特性与其代谢益处密切相关。