Wang DaTing, Wu Ming, Li SiMing, Gao Qian, Zeng QingPing
Tropical Medicine Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
Sci China Life Sci. 2015 May;58(5):451-65. doi: 10.1007/s11427-014-4736-9. Epub 2015 Feb 14.
Calorie restriction (CR) promotes longevity among distinct organisms from yeast to mammals. Although CR-prolonged lifespan is believed to associate with enhanced respiratory activity, it is apparently controversial for accelerated energy consumption regardless of insufficient nutrient intake. In reconciling the contradiction of less food supply versus much metabolite dispense, we revealed a CR-based mode of dual-phase responses that encompass a phase of mitochondrial enhancement (ME) and a phase of post-mitochondrial enhancement (PME), which can be distinguished by the expression patterns and activity dynamics of mitochondrial signatures. ME is characterized by global antioxidative activation, and PME is denoted by systemic metabolic modulation. CR-mediated aging-delaying effects are replicated by artesunate, a semi-synthetic derivative of the antimalarial artemisinin that can alkylate heme-containing proteins, suggesting artesunate-heme conjugation functionally resembles nitric oxide-heme interaction. A correlation of artesunate-heme conjugation with cytochrome c oxidase activation has been established from adduct formation and activity alteration. Exogenous hydrogen peroxide also mimics CR to trigger antioxidant responses, affect signaling cascades, and alter respiratory rhythms, implying hydrogen peroxide is engaged in lifespan extension. Conclusively, artesunate mimics CR-triggered nitric oxide and hydrogen peroxide to induce antioxidative networks for scavenging reactive oxygen species and mitigating oxidative stress, thereby directing metabolic conversion from anabolism to catabolism, maintaining essential metabolic functionality, and extending life expectancy in yeast.
热量限制(CR)可延长从酵母到哺乳动物等不同生物体的寿命。尽管人们认为CR延长寿命与增强呼吸活动有关,但无论营养摄入不足,加速能量消耗显然存在争议。在调和食物供应减少与代谢物大量消耗之间的矛盾时,我们揭示了一种基于CR的双相反应模式,该模式包括线粒体增强(ME)阶段和线粒体后增强(PME)阶段,这两个阶段可通过线粒体特征的表达模式和活性动态来区分。ME的特征是全局抗氧化激活,而PME则以全身代谢调节为特征。青蒿琥酯可复制CR介导的延缓衰老作用,青蒿琥酯是抗疟药物青蒿素的半合成衍生物,可使含血红素的蛋白质烷基化,这表明青蒿琥酯-血红素共轭在功能上类似于一氧化氮-血红素相互作用。从加合物形成和活性改变已确定青蒿琥酯-血红素共轭与细胞色素c氧化酶激活之间的相关性。外源性过氧化氢也模拟CR来触发抗氧化反应、影响信号级联并改变呼吸节律,这意味着过氧化氢参与了寿命延长。总之,青蒿琥酯模拟CR触发的一氧化氮和过氧化氢,诱导抗氧化网络以清除活性氧并减轻氧化应激,从而引导代谢从合成代谢向分解代谢转变,维持基本代谢功能,并延长酵母的预期寿命。