Is warmer better? Decreased oxidative damage in notothenioid fish after long-term acclimation to multiple stressors
Is warmer better? Decreased oxidative damage in notothenioid fish after long-term acclimation to multiple stressors
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DOI：
10.1242/jeb.108431
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发表时间：
2014-09-01
影响因子：
2.8
通讯作者：
Place, Sean P.
中科院分区：
文献类型：
--
作者：
Enzor, Laura A.;Place, Sean P.
南极南极鱼亚目的鱼类进化出了几种独特的适应零下温度的能力。然而，这些适应可能伴随着生理上的权衡，比如对氧化损伤的易感性增加。因此，全球气候变化带来的预期环境扰动有可能显著增加这些特有鱼类的氧化应激水平和细胞损伤。先前对南极鱼的单一应激源研究表明，它们具有适应温度升高的能力，但细胞水平的影响在很大程度上仍然未知。此外，关于南极鱼类对多种变量同时变化的生态相关环境变化的响应能力的信息很少。我们研究了温度升高和P-CO2对bernachchii、Pagothenia borchgrevinki和Trematomus newnesi蛋白质损伤水平的潜在协同效应，并将这些测量结果与过氧化氢酶（CAT）和超氧化物歧化酶（SOD）总酶活性的变化相结合，以测量组织特异性抗氧化能力的变化。我们的研究结果表明，总SOD和CAT活性水平在不同的治疗和组织中只显示出很小的变化。短期适应海水pH降低和温度升高导致氧化损伤显著增加。令人惊讶的是，尽管抗氧化能力没有显著变化，但在长期驯化后，T. bernacchii的细胞损伤恢复到接近基础水平，并显著降低。总的来说，这些数据表明，南极鱼目前保持着必要的抗氧化能力，以抵消预测的未来海洋条件，但目前尚不清楚这种能力是否伴随着生理上的权衡。
Antarctic fish of the suborder Notothenioidei have evolved several unique adaptations to deal with subzero temperatures. However, these adaptations may come with physiological trade-offs, such as an increased susceptibility to oxidative damage. As such, the expected environmental perturbations brought on by global climate change have the potential to significantly increase the level of oxidative stress and cellular damage in these endemic fish. Previous single stressor studies of the notothenioids have shown they possess the capacity to acclimate to increased temperatures, but the cellular-level effects remain largely unknown. Additionally, there is little information on the ability of Antarctic fish to respond to ecologically relevant environmental changes where multiple variables change concomitantly. We have examined the potential synergistic effects that increased temperature and P-CO2 have on the level of protein damage in Trematomus bernacchii, Pagothenia borchgrevinki and Trematomus newnesi, and combined these measurements with changes in total enzymatic activity of catalase (CAT) and superoxide dismutase (SOD) in order to gauge tissue-specific changes in antioxidant capacity. Our findings indicate that total SOD and CAT activity levels displayed only small changes across treatments and tissues. Short-term acclimation to decreased seawater pH and increased temperature resulted in significant increases in oxidative damage. Surprisingly, despite no significant change in antioxidant capacity, cellular damage returned to near-basal levels, and significantly decreased in T. bernacchii, after long-term acclimation. Overall, these data suggest that notothenioid fish currently maintain the antioxidant capacity necessary to offset predicted future ocean conditions, but it remains unclear whether this capacity comes with physiological trade-offs.