脂肪酸氧化驱动了由α-酸酸脱酶的线粒体过氧化生产
Cathryn Grayson1, Ben Faerman1, Olivia Koufos1
1The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada.
The Journal of biological chemistry
|March 13, 2024
概括
阿尔法-甲酸脱酶 (KGDH) 被确定为小鼠肝脏线粒体中线粒体过氧化 (mH2O2) 的主要来源. 这一发现甚至在脂肪酸为线粒体提供燃料时也是如此,这挑战了关于反应性氧物种生成的先前假设.
科学领域:
- 线粒体的生物化学
- 细胞代谢的细胞代谢.
- 反应性氧物种 (ROS) 生产.
背景情况:
- 线粒体的过氧化 (mH2O2) 生产对于细胞信号和功能至关重要.
- 电子输送链 (ETC) 和克雷布斯循环酶是已知的mH2O2生成的贡献者.
- 人们越来越认识到线粒体功能和ROS产生的性别差异.
研究的目的:
- 为了研究alpha-ketoglutarate脱酶 (KGDH) 在小鼠肝脏线粒体中的mH2O2生成中的作用.
- 为了比较KGDH的mH2O2产生能力与ETC综合体的mH2O2产生能力.
- 探索线粒体ROS生产中的潜在的性别二重体.
主要方法:
- 从雄性和雌性C57BL6N小鼠中分离肝脏线粒体.
- 使用各种基质 (脂肪酸,酸盐) 和特定抑制剂 (KMV,S1QEL 1.1,S3QEL 2) 测量mH2O2的产生.
- 对线粒体呼吸和氧化酸化 (OxPhos) 的评估.
主要成果:
- 在男性和女性肝脏线粒体中,KGDH被确定为mH2O2的主要供应者.
- 当线粒体以脂肪酸为燃料时,KGDH产生了mH2O2,前提是马拉酸被用于启动克雷布斯循环.
- 用KMV抑制KGDH显著降低了mH2O2的产生,而ETC抑制剂 (S1,S3) 的影响很小.
- 在ETC复合体I和III的mH2O2生成中观察到两性二态,但KGDH仍然是主要来源.
结论:
- 阿尔法-甲酸脱酶 (KGDH) 是肝脏线粒体中线粒体过氧化的主要来源,无论燃料来源 (包括脂肪酸).
- 这项研究揭示了KGDH在细胞氧化还原平衡中的重要,以前被低估的作用.
- 了解KGDH对mH2O2的贡献对于理解线粒体功能和潜在的治疗点至关重要.
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