Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian 116023, China.
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
Int J Mol Sci. 2024 Oct 22;25(21):11342. doi: 10.3390/ijms252111342.
Glutamate transporters (GLTs) are integral to the glutamatergic system, modulating glutamate homeostasis to enhance resilience and resistance against environmental stress. There are six GLTs identified in the Pacific oyster (), which were categorized into two subfamilies: excitatory amino acid transporters (EAATs) and vesicular glutamate transporters (VGLUTs). The EAATs harbor a GltP domain, while VGLUTs feature an MFS domain, both with conserved sequence and structural characteristics. The expression of GLTs is elevated during the planktonic larval stage compared to the fertilized egg stage and is constitutively expressed in various tissues of adult oysters, suggesting its critical role in both larval development and the physiological processes of adult oysters. Transcriptomic analysis revealed diverse expression patterns of GLTs in oyster gills after 7 days of high-temperature stress, with showing a significant upregulation. A KEGG pathway enrichment analysis identified glutathione metabolism and ferroptosis as prominently enriched pathways. At 48 h after high-temperature stress, the expression levels of Glutathione Peroxidase 4 () and , along with elevated Fe content in the gills, significantly increased. Moreover, the RNAi-mediated the inhibition of expression under high-temperature stress, resulting in a significant reduction in expression and a further increase in Fe accumulation in oyster gills. These results indicate that contributes to the regulation of ferroptosis and redox homeostasis by modulating expression. This study provides new insights into the adaptive mechanisms of bivalves to environmental stress.
谷氨酸转运体（GLTs）是谷氨酸能系统的重要组成部分，调节谷氨酸的稳态，增强对环境应激的适应和抵抗能力。太平洋牡蛎（）中有六种 GLTs，分为两个亚家族：兴奋性氨基酸转运体（EAATs）和囊泡谷氨酸转运体（VGLUTs）。EAATs 含有 GltP 结构域，而 VGLUTs 具有 MFS 结构域，两者都具有保守的序列和结构特征。GLTs 的表达在浮游幼虫期比受精卵期升高，在成年牡蛎的各种组织中持续表达，表明其在幼虫发育和成年牡蛎生理过程中都具有重要作用。转录组分析显示，高温胁迫后 7 天牡蛎鳃中的 GLTs 表达模式多样， 显著上调。KEGG 途径富集分析确定了谷胱甘肽代谢和铁死亡是显著富集的途径。在高温胁迫后 48 小时，鳃中的谷胱甘肽过氧化物酶 4 () 和 的表达水平以及 Fe 含量显著升高。此外，高温胁迫下 RNAi 介导的 表达抑制导致 表达显著降低，牡蛎鳃中铁的积累进一步增加。这些结果表明， 通过调节 表达，有助于铁死亡和氧化还原稳态的调节。本研究为双壳类动物对环境应激的适应机制提供了新的见解。
