Lectin-induced enhancement of superoxide anion production by red tide plankton, Chattonella marina

凝集素诱导赤潮浮游生物、查托氏菌码头超氧阴离子产生的增强

基本信息

批准号：
10660186
负责人：
ODA Tatsuya
金额：
$ 2.24万
依托单位：
Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660186/
关键词：
Red Tide Plankton Reactive Oxygen Species Toxicity Chattonella Raphyidophyceae Lectin

项目摘要

Chattonella marina, a raphidophycean flagellate, is one of the most noxious red tide phytoplankton and is highly toxic to fish, especially to yellowtail Seriola quinqueradiata. Although the precise mechanism of the toxic action of Chattonella sp. remains unclear, it has been demonstrated that a decrease in oxygen partial pressure of arterial blood is the earliest physiological disturbance observed in fish after exposure to C. marina, Physiological and histological studies of fish exposed to C. marina also suggested that the blockade of respiratory water flow through the gill lamellae caused by excessive mucus interferes with O2 transfer, resulting in asphyxia. Recent studies have shown that Chattonella spp. Generate reactive oxygen species (ROS) such as O2-, H2O2, and hydroxyl radical (・OH). Furthermore, it has been reported that Heterosigma akashiwo, which is also classified in a raphidophycean, produces ROS, and showed an oxygen-radical-mediated toxic effect on rainbow trout, Oncorhy … More nchus mykiss. Thus, it is likely that the production of ROS is a common feature of raphidophycean flagellates. In the present study, we found that lectins such as concanavalin A (Con A), wheat germ agglutinin (WGA), and castor bean hemagglutinin (CBH) stimulated C. marina and H. akashiwo to generate enhanced amounts of O2- in a concentration dependent manner. The lectin-specific sugars potently inhibited the lectin-induced increase of O2-production, suggesting that the effects of lectins are mediated mainly through the interaction of these lectins with carbohydrate moiety present on the flagellate cell surface. In contrast to the potent ability of native Con A (tetravalent), succinylated Con A (divalent) showed only slight stimulative effect on these flagellates. O2- production was totally inhibited by treatment with proteinase K for 30 min, without affecting the viabilities of flagellates. These results suggest that cell-surface redox enzyme may be involved in O2- production, and such enzyme is responsible for the lectin-stimulation. Less

查托氏菌 (Chattonella marina) 是一种针藻类鞭毛藻，是最毒的赤潮浮游植物之一，对鱼类，尤其是黄尾鰤 (Seriola quinqueradiata) 具有剧毒。动脉血氧分压降低是鱼类暴露于 C. marina 后观察到的最早的生理紊乱，对暴露于 C. marina 的鱼的生理学和组织学研究也表明过多的粘液导致呼吸水流受阻，干扰 O2 转移，导致窒息。最近的研究表明，查托氏菌会产生活性氧 (ROS)，如 O2-、H2O2 和羟基自由基。 (·OH) 另外，据报道，属于针藻类的赤潮异藻也产生ROS，并表现出活性。氧自由基介导的对虹鳟鱼、Oncorhy ... More nchus mykiss 的毒性作用因此，ROS 的产生可能是针藻类鞭毛虫的一个共同特征。在本研究中，我们发现凝集素如刀豆球蛋白 A (Concanavalin A)。 A)、小麦胚芽凝集素 (WGA) 和蓖麻子血凝素 (CBH) 刺激 C. marina 和 H. akashiwo 产生大量的O2- 以浓度依赖性方式有效抑制凝集素诱导的 O2 产量增加，表明凝集素的作用主要是通过这些凝集素与鞭毛细胞表面上存在的碳水化合物部分的相互作用来介导的。与天然 Con A（四价）的强大能力相反，琥珀酰化 Con A（二价）对这些鞭毛虫仅表现出轻微的刺激作用，而 O2- 的产生则被完全抑制。用蛋白酶 K 处理 30 分钟，不影响鞭毛虫的活力。这些结果表明细胞表面氧化还原酶可能参与 O2- 的产生，并且这种酶负责凝集素刺激。