Improved anti-oxidant activity of superoxide dismutase by direct chemical modification.
Improved anti-oxidant activity of superoxide dismutase by direct chemical modification.
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DOI：
10.1016/j.jconrel.2005.12.005
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发表时间：
2006-03
期刊：
影响因子：
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通讯作者：
N. Ishimoto;Takayuki Nemoto;Keiko Nagayoshi;F. Yamashita;M. Hashida
中科院分区：
文献类型：
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作者：
N. Ishimoto;Takayuki Nemoto;Keiko Nagayoshi;F. Yamashita;M. Hashida
超氧化物歧化酶（SOD）的化学改性衍生物，即，阳离子化的（Cat-SOD）和甘露糖基化的SOD（Man-SOD）被设计用于提高SOD抑制肺泡上皮中活性氧（ROS）介导的损伤的能力。为评价其有效性，采用原代培养的兔肺泡II型细胞建立了百草枯中毒的体外模型。尽管有5.6倍以上的细胞协会比本地的SOD，人SOD没有保护细胞损伤，由于百草枯以下的MTT法评价。与此相反，猫SOD表现出140倍以上的细胞协会比本地SOD和大大抑制百草枯诱导的细胞损伤，以及脂质过氧化。与300 U/ml Cat-SOD孵育2 h，细胞内SOD活性增加5.3倍。胞吞抑制剂细胞松弛素B的存在下，细胞内SOD活性的增加被显着抑制。共聚焦激光扫描荧光显微镜也证实了Cat-SOD的内化。此外，细胞松弛素B的存在完全消除了Cat-SOD对百草枯诱导的细胞损伤的保护作用。总之，这项研究表明，阳离子化的SOD大大提高了其细胞内的交付，因此，产生了显着的保护作用，对ROS介导的损伤肺泡上皮细胞。
Chemically modified derivatives of superoxide dismutase (SOD), i.e., cationized (Cat-SOD) and mannosylated SOD (Man-SOD), were designed to improve an ability of SOD to suppress reactive oxygen species (ROS)-mediated injury in the alveolar epithelium. To evaluate their effectiveness, an in vitro model of paraquat poisoning was developed with primary cultured rabbit alveolar type II cells. Despite a 5.6-fold higher cellular association than native SOD, Man-SOD did not protect cell injury due to paraquat following evaluation by MTT assay. In contrast, Cat-SOD exhibited a 140-fold higher cellular association than native SOD and greatly suppressed paraquat-induced cell injury, as well as lipid peroxidation. Incubation with 300 U/ml Cat-SOD for 2 h increased intracellular SOD activity 5.3-fold. The increase in intracellular SOD activity was significantly inhibited in the presence of cytochalasin B, an endocytosis inhibitor. Internalization of Cat-SOD was also confirmed by confocal laser scanning fluorescein microscopy. In addition, the protective effect of Cat-SOD against paraquat-induced cell injury was completely abolished by the presence of cytochalasin B. In conclusion, this study demonstrated that cationization of SOD greatly enhances its intracellular delivery and, as a consequence, produces a significant protective effect against ROS-mediated injury of the alveolar epithelium.