- 作者: Ching-Jiunn Chen a, Huei-Sheng Huang b, Wen-Chang Chang a
- 作者服務機構: Departments of a PharmacologyY and b Medical Technoiogy, College of Medicine, National Cheng Kung University Tainan, Taiwan, ROC
- 中文摘要: --
- 英文摘要: acid as a stimulator of lipid peroxidation, formation of12-hydroxyeicosatetraenoic acid from arachidonic acidalso significantly decreased in stable transfectants ofoverexpressing PHGPx compared to that in a vector con-trol cell line, indicating that PHGPx could downregulatethe 12-lipoxygenase activity in cells. These results sup-port the hypothesis that PHGPx plays a pivotal role in theregulation of arachidonate metabolism in A431 cells.Phospholipid hydroperoxide glutathione peroxidase(PHGPx), a selenium-dependent glutathione peroxidase,can interact with lipophilic substrates, including phos-pholipid hydroperoxides, fatty acid hydroperoxides andcholesterol hydroperoxides, and can reduce them tohydroxide compounds. It also seems to be a major regu-lator of lipid oxygenation in human epidermoid carcino-ma A431 cells. In order to study the functional role ofPHGPx in the regulation of 12-lipoxygenase and cycloox-ygenase, cDNA of PHGPx was inserted into pcDNA3.1/His, and a plasmid designated as S4 with the His-tagsequence inserted between PHGPx and its 3'-untrans-lated region was constructed. A number of stable trans-fectants of A431 cells that could express the tag-PHGPxwere generated using plasmid S4. Using an intact cellassay system, the metabolism of arachidonic acid toprostaglandin E significantly decreased in stable trans-fectants of overexpressing PHGPx compared to that in avector control cell line. If the intact cell assay was carriedout in the presence of 13-hydroperoxyoctadecadienoic
- 中文關鍵字: --
- 英文關鍵字: Phospholipid hydroperoxide glutathione peroxidase, Cyclooxygenase, 12-Lipoxygenase, A431 cells