Guo Siyuan, Hou Li, Dong Liushu, Nie Xin, Kang Le, Wang Xianhui
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China.
Nat Ecol Evol. 2023 Jun;7(6):914-926. doi: 10.1038/s41559-023-02059-z. Epub 2023 May 8.
Ageing plasticity represents the flexibility of the ageing process in response to non-genetic factors, occurring commonly in animals. However, the regulatory mechanisms underlying ageing plasticity are largely unclear. The density-dependent polyphenism of locusts, Locusta migratoria, displays dramatic lifespan divergence between solitary and gregarious phases, providing a useful system for studying ageing plasticity. Here, we found that gregarious locusts displayed faster locomotor deficits and increased muscle degeneration on ageing than solitary locusts. Comparative transcriptome analysis in flight muscles revealed significant differences in transcriptional patterns on ageing between two phases. RNA interference screening showed that the knockdown of the upregulated PLIN2 gene significantly relieved the ageing-related flight impairments in gregarious locusts. Mechanistically, the gradual upregulation of PLIN2 could induce the accumulation of ectopic lipid droplets and triacylglycerols in flight muscles during the ageing process. Further experiments suggested that ectopic lipid accumulation led to an ageing-related β-oxidation decline through limiting fatty acid transport and content. These findings reveal the key roles of lipid metabolism in the differences of muscle ageing between solitary and gregarious locusts and provide a potential mechanism underlying environment-induced muscle ageing plasticity.
衰老可塑性代表衰老过程对非遗传因素作出反应的灵活性，常见于动物中。然而，衰老可塑性背后的调控机制在很大程度上尚不清楚。蝗虫（飞蝗）的密度依赖性多型现象在独居和群居阶段表现出显著的寿命差异，为研究衰老可塑性提供了一个有用的系统。在此，我们发现群居蝗虫在衰老时比独居蝗虫表现出更快的运动能力缺陷和肌肉退化加剧。飞行肌肉的比较转录组分析揭示了两个阶段衰老时转录模式的显著差异。RNA干扰筛选表明，上调的PLIN2基因的敲低显著缓解了群居蝗虫中与衰老相关的飞行损伤。从机制上讲，PLIN2的逐渐上调可在衰老过程中诱导飞行肌肉中异位脂滴和三酰甘油的积累。进一步的实验表明，异位脂质积累通过限制脂肪酸转运和含量导致与衰老相关的β-氧化下降。这些发现揭示了脂质代谢在独居和群居蝗虫肌肉衰老差异中的关键作用，并提供了环境诱导肌肉衰老可塑性的潜在机制。
