Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
Research and Development Division, Kagome Co., Ltd, Nasushiobara, Tochigi, Japan.
Exp Hematol. 2019 Sep;77:51-60.e1. doi: 10.1016/j.exphem.2019.08.001. Epub 2019 Aug 9.
Sickle cell disease (SCD) is a recessively inherited blood disorder caused by abnormal β-globin production. The β-globin mutation changes erythrocyte morphology into a sickle shape and increases erythrocyte vulnerability to hemolysis. Oxidative stress and concomitant inflammation eventually result in damage to multiple organs. Nrf2 is a master regulator of the oxidative stress response, homeostasis, and metabolism. Keap1 modulates Nrf2 protein levels; Nrf2 inducers alter nuclear Nrf2 levels by interacting with Keap1. Genetic modification of Keap1 helps to reduce inflammation and tissue damage in SCD model mice through Nrf2 induction. Here, we investigated the benefits of a mild and safe Nrf2 agonist, sulforaphane (SFN), in ameliorating SCD pathology in a murine model. SFN is a phytochemical and is found in cruciferous vegetables as its inert precursor, glucoraphanin. We found that dietary SFN administration for 14 days or 2 months increased the expression of Nrf2-dependent cytoprotective genes, but SFN uptake did not have deleterious effects on the food consumption and growth of SCD model mice. SFN ameliorated the liver damage of SCD mice, which could be validated by the rescue of liver function and the significantly reduced liver necrotic area. SFN administration also helped to eliminate heme released from lysed sickle cells. These results indicate that dietary supplementation with SFN relieves SCD symptoms by inducing Nrf2 and support our contention that SFN is a potential drug for the long-term treatment of children with SCD.
镰状细胞病 (SCD) 是一种由异常β-球蛋白产生引起的隐性遗传性血液疾病。β-球蛋白突变使红细胞形态变为镰状,并增加红细胞对溶血的脆弱性。氧化应激和随之而来的炎症最终导致多个器官受损。Nrf2 是氧化应激反应、内稳态和代谢的主要调节剂。Keap1 调节 Nrf2 蛋白水平;Nrf2 诱导剂通过与 Keap1 相互作用改变核 Nrf2 水平。Keap1 的基因修饰通过 Nrf2 诱导有助于减少 SCD 模型小鼠中的炎症和组织损伤。在这里,我们研究了一种温和且安全的 Nrf2 激动剂,即萝卜硫素 (SFN),在改善 SCD 病理中的作用。SFN 是一种植物化学物质,作为其惰性前体存在于十字花科蔬菜中,即萝卜硫苷。我们发现,SFN 饮食给药 14 天或 2 个月可增加 Nrf2 依赖性细胞保护基因的表达,但 SFN 摄取对 SCD 模型小鼠的食物消耗和生长没有不良影响。SFN 改善了 SCD 小鼠的肝损伤,这可以通过肝功能的恢复和肝脏坏死面积的显著减少来验证。SFN 给药还有助于消除从裂解的镰状细胞中释放的血红素。这些结果表明,SFN 通过诱导 Nrf2 来缓解 SCD 症状,并支持我们的观点,即 SFN 是一种治疗 SCD 儿童的潜在药物。