Marine Biotechnology & Bioresource Research Department, Korea Institute of Ocean Science & Technology (KIOST), Busan 49111, Republic of Korea.
Département des Sciences, Université Sainte-Anne, Church Point, NS B0W 1M0, Canada.
Comp Biochem Physiol A Mol Integr Physiol. 2025 Jan;299:111775. doi: 10.1016/j.cbpa.2024.111775. Epub 2024 Nov 12.
In this study, we aimed to understand the effects of changes in temperature on biochemical and molecular responses associated with the antioxidant defense system in the bay scallop, Argopecten irradians. We measured the contents of HO and malondialdehyde (MDA), as well as the activities of antioxidant enzymes (e.g., glutathione S-transferase [GST], superoxide dismutase [SOD], and catalase [CAT]), and the regulation of stress-related genes (e.g., GST, SOD, CAT, and heat shock protein 70 [HSP70]). In addition, total antioxidant capacity (TAC) was examined in scallops exposed to different temperatures. A. irradians showed high levels of HO and MDA in response to acute thermal stress (48 and 72 h of exposure). Temperature changes also led to a significant increase in antioxidant enzyme activity and mRNA expression levels in A. irradians. Interestingly, the TAC increased in response to acute thermal stress (28 °C) for up to 12 h and decreased thereafter. The oxidative stress induced by high temperatures could not be alleviated by an increase in levels of antioxidant enzymes, such as GST, SOD, and CAT, resulting in high levels of HO and MDA and low levels of TAC. In addition, significant changes (P < 0.05) in HSP70 levels were observed in response to changes in temperature, suggesting that HSP70 played an important role in the heat tolerance of A. irradians. In conclusion, A. irradians exhibits a greater degree of oxidative stress responses in high-temperature environments than that in low-temperature environments. Overall, these findings indicate that temperature changes lead to oxidative stress, resulting in cellular damage and activation of the antioxidant defense system in bay scallops. Further experiments are required to elucidate other antioxidants and fully understand the redox system in A. irradians.
在这项研究中，我们旨在了解温度变化对海湾扇贝抗氧化防御系统相关生化和分子反应的影响。我们测量了 HO 和丙二醛 (MDA) 的含量，以及抗氧化酶（如谷胱甘肽 S-转移酶 [GST]、超氧化物歧化酶 [SOD] 和过氧化氢酶 [CAT]）的活性，以及应激相关基因（如 GST、SOD、CAT 和热休克蛋白 70 [HSP70]）的调控。此外，还检测了暴露于不同温度下扇贝的总抗氧化能力 (TAC)。急性热应激（暴露 48 和 72 小时）导致 A. irradians 中 HO 和 MDA 水平升高。温度变化还导致 A. irradians 中抗氧化酶活性和 mRNA 表达水平显著增加。有趣的是，TAC 在急性热应激（28°C）下增加长达 12 小时，此后降低。高温引起的氧化应激不能通过增加 GST、SOD 和 CAT 等抗氧化酶的水平来缓解，导致 HO 和 MDA 水平升高和 TAC 水平降低。此外，HSP70 水平也因温度变化而发生显著变化（P<0.05），表明 HSP70 在 A. irradians 的耐热性中发挥重要作用。总之，A. irradians 在高温环境中比在低温环境中表现出更大程度的氧化应激反应。总的来说，这些发现表明温度变化导致氧化应激，导致贝类细胞损伤和抗氧化防御系统激活。需要进一步的实验来阐明其他抗氧化剂并充分了解 A. irradians 的氧化还原系统。
