刺参不同组织中MnSOD基因在脂多糖刺激下的定量表达分析

刺参由于其重要的经济价值和药用价值，已经成为我国海水养殖的重要种类。MnSOD对于增强吞噬细胞防御能力和整个机体的免疫功能具有重要作用，与生物体抵御病毒细菌等能力密切相关。通过研究在脂多糖刺激下MnSOD基因的定量表达情况，分析MnSOD在刺参免疫系统中的作用。结果显示：MnSOD基因的表达量由肠、肌肉到管足逐渐降低，体壁的表达量与体腔液基本一致。当刺参暴露于脂多糖中时，除肠以外其他的四种组织中MnSOD基因均出现过表达。其中，体腔液和体壁组织中MnSOD基因的表达量于12 h达到峰值；肌肉和管足中MnSOD基因的表达量于48 h达到峰值；体腔液中MnSOD基因的表达量于12 h达到对照组的4 115倍，而肠组织中MnSOD基因的表达量在48 h的实验过程中呈波动性降低。总体上来说，在脂多糖刺激下刺参各组织中MnSOD基因的表达量呈规律性波动。实验结果表明：在脂多糖刺激下刺参个体会产生强烈的抗氧化反应以保护刺参免受病原微生物的感染。

Quantatative Expresion Analysis of Manganese Superoxide Dismutase Gene in Different Tissues of Sea Cucumber Apostichopus japonicus under Lipopolysaccharide Stimulation

The sea cucumber Apostichopus japonicus has become an important aquaculture species because of its high economic and medicinal value. Antioxidant enzymes play important roles in antioxidant responses caused by metabolic process or pathogen invasion. To better understand how A. japonicus copes with LPS challenge, the MnSOD mRNA expression was demonstrated in multiple tissues of sea cucumber under normal condition and LPS challenge. The MnSOD gene expression in different tissues indicated that high expression was observed in intestines, followed by muscle and tube foot in sea cucumber. Relatively high expression was found in body wall and coelomocytes. Low expression was shown in tentacle and respiratory tree. In this study, induction of MnSOD in A. japonicus, as measured by mRNA level, was affected by duration of LPS challenge. The MnSOD gene was over-expressed in other 4 parts except for intestines, when specimens were exposed to LPS challenge. However, the MnSOD mRNA expression levels in the coelomocytes and body wall peaked at 12 h after exposure to LPS, whereas the peak in muscle and tube foot appeared at 48 h. The value of MnSOD mRNA expression levels at 12 h in the coelomocytes was 4115-fold higher than that in the control treatment. In contrast, the MnSOD gene showed a reduced expression for LPS treated sea cucumbers during 48 h in intestines. The level of MnSOD expression showed a certain disciplinary fluctuation. The data suggested that a strong antioxidant reaction when the sea cucumber was challenged by LPS, which might be related to protection of sea cucumber against microbial infection.