Sirtuins are a class of NAD⁺-dependent deacylases, with known regulatory roles in energy metabolism and cellular stress responses in vertebrates. Previous work using marine mussels have suggested a similar role in invertebrates, providing a potential mechanism linking food availability and thermal sensitivity in Mytilids. Sirtuin inhibitors affect mussels' recovery from environmental stressors, including acute heat shock and well-fed mussels exposed to sirtuin inhibitors and/or acute heat shock respond differently than poorly fed mussels, at the protein and whole-organism levels. While this implies a relationship between sirtuins, food availability, and temperature, the direct effects of sirtuin inhibitors (nicotinamide and suramin) on sirtuin activity or their putative effectors have not been explicitly tested. In this study, adult Mytilus californianus were acclimated to a low or high food availability and exposed to one of the following treatments: control, acute heat shock, sirtuin inhibitors, or acute heat shock and sirtuin inhibitors. Mussels increased sirtuin activity during early recovery (5 h) from sirtuin inhibition and acute heat shock, but only if acclimated to a high food availability. Redox balance was also impacted in mussels acclimated to high food availability and exposed to sirtuin inhibitors, signifying interactions between ration, acute heat shock, and sirtuin inhibitors. Additionally, we found a correlation between sirtuin and superoxide dismutase activities, suggesting a potential regulatory role of oxidative stress by sirtuins. Following prolonged recovery (17 h), we found increased sirtuin activity in mussels acclimated to low food availability, indicating that endogenous sirtuin activity may be related to food availability in mussels.

Sirtuins 是一类 NAD ⁺依赖性脱酰酶，在脊椎动物的能量代谢和细胞应激反应中具有已知的调节作用。先前使用海洋贻贝的研究表明，无脊椎动物也具有类似的作用，这提供了将贻贝的食物可用性和热敏感性联系起来的潜在机制。Sirtuin抑制剂影响贻贝从环境应激源中恢复，包括急性热休克和暴露于sirtuin抑制剂的喂养良好的贻贝和/或急性热休克在蛋白质和整体生物体水平上的反应与喂养不良的贻贝不同。虽然这意味着沉默调节蛋白、食物供应和温度之间存在关系，但沉默调节蛋白抑制剂（烟酰胺和苏拉明）对沉默调节蛋白活性或其假定效应物的直接影响尚未得到明确测试。在这项研究中，成年加州贻贝适应了低或高的食物供应，并接受以下治疗之一：对照、急性热休克、去乙酰化酶抑制剂，或急性热休克和去乙酰化酶抑制剂。贻贝在从沉默调节蛋白抑制和急性热休克中恢复的早期（5小时）期间增加了沉默调节蛋白的活性，但前提是适应了高食物可用性。适应高食物供应并暴露于沉默调节蛋白抑制剂的贻贝的氧化还原平衡也受到影响，这表明定量、急性热休克和沉默调节蛋白抑制剂之间存在相互作用。此外，我们发现去乙酰化酶和超氧化物歧化酶活性之间存在相关性，表明去乙酰化酶对氧化应激具有潜在的调节作用。经过长时间的恢复（17小时），我们发现适应低食物供应的贻贝中的sirtuin活性增加，表明内源sirtuin活性可能与贻贝的食物供应有关。