Moreira Daniel C, Hermes-Lima Marcelo
Research Center in Morphology and Applied Immunology, Faculty of Medicine, University of Brasilia, Brasilia 70910-900, Brazil.
Cell Biology Department, Biological Sciences Institute, University of Brasilia, Brasilia 70910-900, Brazil.
Antioxidants (Basel). 2024 Aug 7;13(8):959. doi: 10.3390/antiox13080959.
Complete insect metamorphosis requires substantial metabolic and physiological adjustments. Although oxidative stress has been implicated in metamorphosis, details on redox metabolism during larva-to-pupa and pupa-to-adult remain scarce. This study explores redox metabolism during metamorphosis of a lepidopteran (), focusing on core metabolism, antioxidant systems and oxidative stress. The larva-to-pupa transition was characterized by increased lactate dehydrogenase and glutathione peroxidase (GPX) activities, coupled with depletion of reduced glutathione (GSH), high disulfide-to-total-glutathione ratio (GSSG/tGSH), and increased lipid peroxidation. As metamorphosis progressed, metabolic enzyme activities, citrate synthase and glucose 6-phosphate dehydrogenase increased, indicating heightened oxidative metabolism associated with adult development. Concurrently, GSH and GPX levels returned to larval levels and GSSG/tGSH reached its most reduced state right before adult emergence. Adult emergence was marked by a further increase in oxidative metabolism, accompanied by redox imbalance and enhanced antioxidant mechanisms. These findings highlight a fluctuation in redox balance throughout metamorphosis, with periods of oxidative eustress followed by compensatory antioxidant responses. This study is the first to identify concurrent changes in metabolism, antioxidants, redox balance and oxidative stress throughout metamorphosis. Our findings extend knowledge on redox metabolism adjustments and highlight redox adaptations and oxidative stress as natural components of complete insect metamorphosis.
完全变态昆虫需要进行大量的代谢和生理调节。尽管氧化应激与变态过程有关，但关于幼虫到蛹以及蛹到成虫阶段的氧化还原代谢细节仍然很少。本研究探讨了一种鳞翅目昆虫变态过程中的氧化还原代谢，重点关注核心代谢、抗氧化系统和氧化应激。幼虫到蛹的转变表现为乳酸脱氢酶和谷胱甘肽过氧化物酶（GPX）活性增加，同时还原型谷胱甘肽（GSH）消耗、二硫键与总谷胱甘肽比率（GSSG/tGSH）升高以及脂质过氧化增加。随着变态的进行，代谢酶活性、柠檬酸合酶和葡萄糖6-磷酸脱氢酶增加，表明与成虫发育相关的氧化代谢增强。同时，GSH和GPX水平恢复到幼虫水平，GSSG/tGSH在成虫羽化前达到最还原状态。成虫羽化的特点是氧化代谢进一步增加，同时伴有氧化还原失衡和抗氧化机制增强。这些发现突出了整个变态过程中氧化还原平衡的波动，先是氧化适度应激期，随后是补偿性抗氧化反应。本研究首次确定了整个变态过程中代谢、抗氧化剂、氧化还原平衡和氧化应激的同时变化。我们的发现扩展了关于氧化还原代谢调节的知识，并强调氧化还原适应和氧化应激是完全变态昆虫的自然组成部分。
