Masaki H, Okano Y, Sakurai H
Shiga Research, Noevir Co., Ltd, Japan.
Arch Dermatol Res. 1998 Mar;290(3):113-8. doi: 10.1007/s004030050275.
The purpose of this study was to elucidate the differential contribution of catalase and glutathione peroxidase (GSH-Px) to H2O2 scavenging in cultured human dermal fibroblasts. Responses of the cells in terms of both enzyme activities were examined by using two sorts of inhibitors, 3-amino-1H-1,2,4-triazole (AT) for catalase and DL-buthionine-[S,R]-sulfoximine (BSO) for GSH-Px, under exposure to H2O2 or ultraviolet (UV) B radiation. AT treatment resulted in a decrease in H2O2 scavenging activity, while BSO treatment did not affect H2O2 scavenging. When fibroblasts were exposed to a low concentration of H2O2 (100 microM). AT treatment resulted in a significant decrease in cell survival, but BSO treatment did not affect survival. At higher concentrations of H2O2 ranging from 500 microM to 1 mM, BSO-treated fibroblasts showed reduced survival. In addition, AT treatment was much more cytotoxic in the presence of UVB than BSO treatment. The intracellular levels of H2O2 in fibroblasts treated with AT or BSO were also determined. BSO-treated cells showed similar H2O2 levels to control cells, but the intracellular H2O2 levels of AT-treated fibroblasts were 1.4-fold higher than found in control cells. These results with human dermal fibroblasts indicate that catalase acts as a primary defence against oxidative stress from exogenous or endogenous H2O2 at low concentrations. In contrast, GSH-Px helps protect the cell from damage during exposure to high concentrations of H2O2.
本研究的目的是阐明过氧化氢酶和谷胱甘肽过氧化物酶（GSH-Px）在培养的人皮肤成纤维细胞中对过氧化氢清除的不同贡献。在暴露于过氧化氢或紫外线（UV）B辐射的情况下，使用两种抑制剂，即针对过氧化氢酶的3-氨基-1H-1,2,4-三唑（AT）和针对GSH-Px的DL-丁硫氨酸-[S，R]-亚砜亚胺（BSO），检测了细胞在两种酶活性方面的反应。AT处理导致过氧化氢清除活性降低，而BSO处理不影响过氧化氢清除。当成纤维细胞暴露于低浓度的过氧化氢（100 microM）时，AT处理导致细胞存活率显著降低，但BSO处理不影响存活率。在500 microM至1 mM的较高过氧化氢浓度下，经BSO处理的成纤维细胞存活率降低。此外，在紫外线B存在的情况下，AT处理比BSO处理具有更强的细胞毒性。还测定了用AT或BSO处理的成纤维细胞内过氧化氢的水平。经BSO处理的细胞显示出与对照细胞相似的过氧化氢水平，但经AT处理的成纤维细胞内过氧化氢水平比对照细胞高1.4倍。这些用人皮肤成纤维细胞得到的结果表明，过氧化氢酶在低浓度下作为对外源性或内源性过氧化氢氧化应激的主要防御机制。相比之下，GSH-Px有助于在细胞暴露于高浓度过氧化氢期间保护细胞免受损伤。
