The impact of acute thermal stress on the metabolome in the black rockfish (Sebastes schlegelii)
The impact of acute thermal stress on the metabolome in the black rockfish (Sebastes schlegelii)
复制标题
急性热应激对黑石斑鱼（Sebastes schlegelii）代谢组的影响
作者：
Ji Zhao;Min Song;Haishen Wen;Yun Li;Jifang Li;Lanmin Li;Ya-Xiong Tao
水温的急剧变化给水产养殖业造成了巨大的经济损失。采用气相色谱-飞行时间-质谱仪(GC-TOF-MS)代谢组学方法，研究了高温(27℃)和低温(5℃)条件下黑鱼血清对正常16℃水温和高温(27℃)的整体代谢响应。通过与代谢组数据库的比对，鉴定了2 60种不同丰度的代谢物，并通过正交偏最小二乘判别分析，分别在27℃和5℃下对黑鱼血清进行了处理，得到了36种具有统计学意义的4种代谢物。与能量代谢有关的代谢物和大部分碱性氨基酸在急性高温暴露后显著增加(P<；0.05)，而低温组无明显变化。然而，一些脂肪酸在低温胁迫下有升高的趋势(P<；0.05)，而在高温条件下没有表现出明显的变化，这表明急性高温和低温暴露引起了不同的生理反应。为了更清楚地解释代谢的变化，用实时定量聚合酶链式反应分析了泛素(UB)、低氧诱导因子(HIF)、乳酸脱氢酶(LDH)和乙酰辅酶A羧基酶(Acac)。高温组UB、HIF和LDH高表达(P<；0.05)，低温组无明显变化。而acac基因在高温和低温条件下的表达均无明显变化。这些结果表明，高温组高代谢率导致的能量需求急剧增加，导致HIF1α水平升高，从而加强糖酵解提供能量的过程。此外，蛋白质变性导致组织中UB的高表达或作为热应激时能量缺乏的补充，加速了组织中蛋白质的降解。然而，在寒冷环境中，乌骨鱼的代谢反应途径不涉及上述机制，可能是代谢率低的原因，而较强的耐寒性可能与脂质代谢有关。我们的发现提供了黑色岩鱼暴露在急性高温和低温水中时的潜在代谢谱，并为宿主对热应激的代谢和分子反应提供了一些启示。
Acute change in water temperature causes heavy economic loss in aquaculture. The present study investigated the metabolic and molecular effect of acute thermal stress on black rockfish (Sebastes schlegelii).Gas Spectrometry-Time-of-Flight-Mass Spectrometry (GC-TOF-MS) based metabolomics was used to investigate a global metabolic response of black rockfish serum to the high water temperature (27 °C) and the low water temperature (5 °C) compared to normal 16°C water temperature. 260 varied abundance of annotated metabolites were identified through the alignment to metabolome database, and thirty-six and thirsty-four metabolites of which concentrations had a statistically change were obtained through the orthogonal partial least squares discriminant analysis (OPLS-DA) in the serum of black rockfish under the thermal treatment at 27 °C and 5 °C, respectively. Metabolites involved in energy metabolism and a large portion of basic amino acids had a significant increase caused by acutely exposure to high temperature (P<0.05) and no change occurred in the low temperature group. However, some fatty acids was examined to have an increase raised by cold stress (P<0.05) and no effect was detected in the high temperature, which indicated that acute high and low temperature exposure posed different physiological response. In order to clearly interpret the changed metabolic profile, ubiquitin (UB), hypoxia-inducible factor (HIF), lactate dehydrogenase (LDH), and acetyl-CoA carboxylase (ACAC) were analyzed by quantitative real-time PCR. High expression levels of UB, HIF, and LDH (P<0.05) were detected in high temperature group and no change in low temperature. However, ACAC gene expression had no change both in high and low temperature. These results indicated that the sharply increased energy demand caused by high metabolic rate in high temperature group induced the high level of HIF1α which could strengthen the process of glycolysis to provide energy. In addition, the protein degradation in tissues was speed up as the result of high expression of UB caused by protein denaturation or to be the supplement for energy default when black rockfish were acutely exposed to heat stress. Nevertheless, when exposed to cold environment, the metabolic responsive way of black rockfish did not involve the above mechanisms as the likely reason of low metabolic rate and the strong cold tolerance might related to the lipid metabolism. Our findings provide a potential metabolic profile for black rockfish when exposed to acute high and low temperature water, and shed some light on host metabolic and molecular response to thermal stress.