State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
College of Food Science and Technology, Henan University of Technology, Zhengzhou, Henan 450001, China.
Food Funct. 2020 Feb 26;11(2):1764-1778. doi: 10.1039/c9fo02819f.
Dietary methionine restriction (MR) has been reported to extend lifespan, reduce obesity and decrease oxidative damage to mtDNA in the heart of rats, and increase endogenous hydrogen sulfide (H2S) production in the liver and blood. H2S has many potential benefits in the pathophysiology of the cardiovascular system. MR also increases the level of homocysteine (Hcy) in the liver and plasma, but elevated plasma Hcy is a risk factor for cardiovascular disease. Therefore, this study aimed to determine the effect of MR on cardiac function and metabolic status in obese middle-aged mice and its possible mechanisms. C57BL/6J mice (aged approximately 28 weeks) were divided into six dietary groups: CON (0.86% methionine + 4% fat), CMR40 (0.52% methionine + 4% fat), CMR80 (0.17% methionine + 4% fat), HFD (0.86% methionine + 24% fat), HMR40 (0.52% methionine + 24% fat) and HMR80 (0.17% methionine + 24% fat) for 15 consecutive weeks. Our results showed that 80% MR improves systolic dysfunction in middle-aged obese mice and enhances myocardial energy metabolism. 80% MR also reduces myocardial oxidative stress and improves inflammatory response. In addition, 80% MR increased mice Hcy levels and activated remethylation and transsulfur pathways of Hcy and promoted endogenous H2S production in the heart. 40% MR has the same trend, but is not significant. Moreover 40% MR at variance with 80% MR, did not decrease the body weight in both control and high-fat diet mice. These findings suggest that MR can improve myocardial energy metabolism, reduce heart inflammation and oxidative stress by increasing cardiac H2S production, and improve cardiac dysfunction in middle-aged obese mice.
限制饮食蛋氨酸（MR）已被报道可延长寿命、减少肥胖、减少心脏中线粒体 DNA 的氧化损伤，并增加肝脏和血液中的内源性硫化氢（H2S）生成。H2S 在心血管系统的病理生理学中有许多潜在的益处。MR 还会增加肝脏和血浆中的同型半胱氨酸（Hcy）水平，但升高的血浆 Hcy 是心血管疾病的一个危险因素。因此，本研究旨在确定 MR 对肥胖中年小鼠心脏功能和代谢状态的影响及其可能的机制。C57BL/6J 小鼠（约 28 周龄）分为六组饮食：CON（0.86%蛋氨酸+4%脂肪）、CMR40（0.52%蛋氨酸+4%脂肪）、CMR80（0.17%蛋氨酸+4%脂肪）、HFD（0.86%蛋氨酸+24%脂肪）、HMR40（0.52%蛋氨酸+24%脂肪）和 HMR80（0.17%蛋氨酸+24%脂肪），连续喂养 15 周。我们的结果表明，80%MR 可改善中年肥胖小鼠的收缩功能障碍，并增强心肌能量代谢。80%MR 还可降低心肌氧化应激并改善炎症反应。此外，80%MR 增加了小鼠 Hcy 水平，并激活了 Hcy 的再甲基化和转硫途径，促进了心脏内源性 H2S 的产生。40%MR 有相同的趋势，但不显著。此外，40%MR 与 80%MR 不同，它没有降低对照组和高脂肪饮食组小鼠的体重。这些发现表明，MR 通过增加心脏 H2S 的产生，改善心肌能量代谢，减少心脏炎症和氧化应激，从而改善中年肥胖小鼠的心脏功能障碍。
