Department of Zoology, Stockholm University, Stockholm, Sweden.
Department of Zoology, Stockholm University, Stockholm, Sweden.
Insect Biochem Mol Biol. 2021 Jun;133:103495. doi: 10.1016/j.ibmb.2020.103495. Epub 2020 Nov 7.
Excess consumption of high-fat diet (HFD) is likely to result in obesity and increases the predisposition to associated health disorders. Drosophila melanogaster has emerged as an important model to study the effects of HFD on metabolism, gut function, behavior, and ageing. In this study, we investigated the effects of HFD on physiology and behavior of female flies at different time-points over several weeks. We found that HFD decreases lifespan, and also with age leads to accelerated decline of climbing ability in both virgins and mated flies. In virgins HFD also increased sleep fragmentation with age. Furthermore, long-term exposure to HFD results in elevated adipokinetic hormone (AKH) transcript levels and an enlarged crop with increased lipid stores. We detected no long-term effects of HFD on body mass, or levels of triacylglycerides (TAG), glycogen or glucose, although fecundity was diminished. However, one week of HFD resulted in decreased body mass and elevated TAG levels in mated flies. Finally, we investigated the role of AKH in regulating effects of HFD during aging. Both with normal diet (ND) and HFD, Akh mutant flies displayed increased longevity compared to control flies. However, both mutants and controls showed shortened lifespan on HFD compared to ND. In flies exposed to ND, fecundity is decreased in Akh mutants compared to controls after one week, but increased after three weeks. However, HFD leads to a similar decrease in fecundity in both genotypes after both exposure times. Thus, long-term exposure to HFD increases AKH signaling, impairs lifespan and fecundity and augments age-related behavioral senescence.
过量摄入高脂肪饮食（HFD）可能导致肥胖，并增加相关健康疾病的易感性。黑腹果蝇已成为研究 HFD 对代谢、肠道功能、行为和衰老影响的重要模型。在这项研究中，我们研究了 HFD 对不同时间点、数周内雌性果蝇的生理和行为的影响。我们发现 HFD 会降低寿命，并且随着年龄的增长，会加速处女蝇和交配蝇的攀爬能力下降。在处女蝇中，HFD 还会随着年龄的增长增加睡眠片段化。此外，长期暴露于 HFD 会导致脂肪激活激素（AKH）转录水平升高，嗉囊增大，脂质储存增加。我们没有检测到 HFD 对体重或三酰基甘油（TAG）、糖原或葡萄糖水平的长期影响，尽管生育力下降。然而，交配后的果蝇在接受 HFD 一周后体重减轻，TAG 水平升高。最后，我们研究了 AKH 在调节衰老过程中 HFD 作用的角色。在正常饮食（ND）和 HFD 下，与对照果蝇相比，Akh 突变果蝇的寿命都延长了。然而，与 ND 相比，无论是突变体还是对照果蝇在 HFD 下的寿命都缩短了。在接受 ND 的果蝇中，Akh 突变体的生育力在一周后比对照果蝇下降，但在三周后增加。然而，HFD 会导致两种基因型在两种暴露时间后的生育力都相似下降。因此，长期暴露于 HFD 会增加 AKH 信号，损害寿命和生育力，并加剧与年龄相关的行为衰老。
