Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Austria.
Department of Ecology Physiology Ethology, Pluridisciplinary Institute Hubert Curien, UMR 7179 CNRS/UdS, Strasbourg, France.
J Therm Biol. 2024 Jul;123:103913. doi: 10.1016/j.jtherbio.2024.103913. Epub 2024 Jul 5.
Oxidative stress is thought to be one of the main causes of ageing as it progressively damages cell components throughout life, eventually causing cellular failure and apoptosis. In many organisms, telomeres shorten throughout life under the effect of, amongst other factors, oxidative stress, and are therefore commonly used as marker of biological ageing. However, hibernators, which are regularly exposed to acute oxidative stress when rewarming from torpor, are unexpectedly long-lived. In this review, we explore the causes of oxidative stress associated with hibernation and its impact on telomere dynamics in different taxa, focussing on hibernating rodents. We then speculate on the adaptive mechanisms of hibernators to compensate for the effects of oxidative stress, which may explain their increased longevity. Because winter hibernation appears to be associated with high oxidative stress, hibernators, particularly rodents, may periodically invest in repair mechanisms and antioxidant defences, resulting in seasonal variations in telomere lengths. This research shows how species with a slow life-history strategy deal with large changes in oxidative stress, unifying evolutionary and physiological theories of ageing. Because of the marked seasonal variation in telomere length, we also draw attention when using telomeres as markers for biological aging in seasonal heterotherms and possibly in other highly seasonal species.
氧化应激被认为是衰老的主要原因之一，因为它会在生命过程中逐渐损害细胞成分，最终导致细胞衰竭和细胞凋亡。在许多生物体中，端粒在氧化应激等因素的影响下，随着生命的延续而逐渐缩短，因此常被用作生物衰老的标志物。然而，冬眠动物在从冬眠中苏醒时经常会受到急性氧化应激的影响，但其寿命却出人意料地长。在这篇综述中，我们探讨了与冬眠相关的氧化应激的原因及其对不同分类群端粒动力学的影响，重点关注冬眠的啮齿动物。然后，我们推测了冬眠动物补偿氧化应激影响的适应机制，这可能解释了它们寿命的延长。由于冬季冬眠似乎与高氧化应激有关，冬眠动物，特别是啮齿动物，可能会周期性地投资于修复机制和抗氧化防御，从而导致端粒长度的季节性变化。这项研究展示了具有缓慢生活史策略的物种如何应对氧化应激的巨大变化，统一了衰老的进化和生理理论。由于端粒长度的季节性变化明显，我们还提请注意在季节性异温动物和可能在其他高度季节性物种中使用端粒作为生物衰老标志物时的注意事项。
