University College Institute of Ophthalmology, London, UK.
School of Science, University of Greenwich, London, UK.
Sci Rep. 2019 Sep 25;9(1):13898. doi: 10.1038/s41598-019-48383-y.
Mitochondria provide energy for cellular function. We examine daily changing patterns of mitochondrial function and metabolism in Drosophila in vivo in terms of their complex (I-IV) activity, ATP production, glycolysis, and whole fly respiration in the morning, afternoon and night. Complex activity and respiration showed significant and unexpected variation, peaking in the afternoon. However, ATP levels by contrast are >40% greater in the morning and lowest at night when glycolysis peaks. Complex activity modulation was at the protein level with no evidence for differential transcription over the day. Timing differences between increased ATP production and peaks of complex activity may result from more efficient ATP production early in the day leaving complex activity with spare capacity. Optical stimulation of mitochondria is only possible in the mornings when there is such spare capacity. These results provide first evidence of shifts in cellular energy capacity at the organism level. Understanding their translation may be significant to the chosen timing of energy demanding interventions to improve function and health.
线粒体为细胞功能提供能量。我们研究了果蝇体内线粒体功能和代谢的日常变化模式，包括它们的复合物（I-IV）活性、ATP 产生、糖酵解以及整个果蝇在早晨、下午和晚上的呼吸作用。复合物活性和呼吸作用显示出显著且出乎意料的变化，在下午达到峰值。然而，与早晨相比，ATP 水平高出 >40%，而在糖酵解达到峰值的晚上则最低。复合物活性的调节是在蛋白质水平上进行的，没有证据表明白天转录有差异。增加的 ATP 产生和复合物活性峰值之间的时间差异可能是由于早晨 ATP 产生效率更高，使复合物活性具有剩余的容量。只有在早上有这种剩余容量时，才能对线粒体进行光学刺激。这些结果首次提供了在机体水平上细胞能量容量变化的证据。了解它们的转化可能对选择需要能量的干预措施以改善功能和健康的时间具有重要意义。
