Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil; Research Center in Morphology and Applied Immunology (NuPMIA), Faculty of Medicine, University of Brasilia, Brasilia, Brazil.
Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil.
Comp Biochem Physiol A Mol Integr Physiol. 2023 Feb;276:111341. doi: 10.1016/j.cbpa.2022.111341. Epub 2022 Nov 8.
This commentary acknowledges the contributions of the Ukrainian biologist, Dr. Volodymyr Lushchak, to the understanding of the physiological adaptive strategy called "Preparation for Oxidative Stress" (POS). In the 1990s, various studies revealed that activities of antioxidant enzymes rose in animals under hypometabolic conditions. These timely observations allowed scientists to propose that this increase could prepare animals for reoxygenation events following the release of oxygen restriction, but in doing so, would trigger oxidative damage, hence the use of the term "preparation". Over next 25 years, the phenomenon was described in detail in more than one hundred studies of animals under conditions of aestivation, hypoxia/anoxia, freezing, severe dehydration, ultraviolet exposure, air exposure of water-breathing animals, salinity stress, and others. The POS phenomenon remained without a mechanistic explanation until 2013, when it was proposed that a small increase in oxyradical formation during hypoxia exposure (in hypoxia-tolerant animals) could activate redox-sensitive transcription factors that, in turn, would initiate transcription and translation of antioxidant enzymes. Dr. Lushchak, who studied goldfish under severe hypoxia in the 1990s, had actually proposed the increased production of oxyradicals under this condition and concluded that it would lead to an upregulation of antioxidant enzymes, the hallmark of the POS strategy. However, his research partner at the time, Dr. Hermes-Lima, thought the idea did not have sufficient evidence to support it and recommended the removal of this explanation. In those days, the main line of thinking was that increased oxyradical formation under hypoxia was "impossible". So, as it turns out, the ideas of Dr. Lushchak were well ahead of his time. It then took >10 years before the biochemical and molecular mechanisms responsible for triggering the POS response were clarified. In the present article, this fascinating history is described to highlight Dr. Lushchak's contributions and insights about the POS theory.
这篇评论承认了乌克兰生物学家弗拉基米尔·卢什察克博士对被称为“氧化应激预备”（POS）的生理适应策略的贡献。在 20 世纪 90 年代，各种研究表明，在代谢降低的情况下，动物体内抗氧化酶的活性会升高。这些及时的观察结果使科学家们提出，这种增加可以使动物为氧限制释放后的再氧化事件做好准备，但这样做会引发氧化损伤，因此使用了“预备”一词。在接下来的 25 年里，这一现象在 100 多项关于动物在夏眠、缺氧/缺氧、冻结、严重脱水、紫外线暴露、呼吸空气的水生动物暴露于空气、盐度应激等条件下的研究中得到了详细描述。直到 2013 年，当提出在缺氧暴露期间（在耐缺氧动物中）小幅度增加氧自由基形成可以激活氧化还原敏感转录因子，而这些转录因子又会启动抗氧化酶的转录和翻译时，POS 现象仍然没有得到机制解释。卢什察克博士在 20 世纪 90 年代就曾在严重缺氧的情况下研究金鱼，实际上他提出了在这种情况下氧自由基产量增加，并得出结论认为这将导致抗氧化酶的上调，这是 POS 策略的标志。然而，当时他的研究伙伴 Hermes-Lima 博士认为这个想法没有足够的证据支持，并建议删除这个解释。当时，主要的思路是认为缺氧下氧自由基形成的增加“是不可能的”。因此，事实证明，卢什察克博士的想法远远领先于他所处的时代。直到 10 多年后，才阐明了触发 POS 反应的生化和分子机制。在本文中，描述了这一引人入胜的历史，以突出卢什察克博士对 POS 理论的贡献和见解。
