Non-selective distribution of isomeric cholesterol hydroperoxides to microdomains in cell membranes and activation of matrix metalloproteinase activity in a model of dermal cells
Non-selective distribution of isomeric cholesterol hydroperoxides to microdomains in cell membranes and activation of matrix metalloproteinase activity in a model of dermal cells
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DOI：
10.1016/j.chemphyslip.2013.05.004
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发表时间：
2013-09-01
影响因子：
3.4
通讯作者：
Terao, Junji
中科院分区：
文献类型：
--
作者：
Nakamura, Toshiyuki;Noma, Ayako;Terao, Junji
胆固醇氢过氧化物（chohs）是皮肤暴露在紫外线（UV）光照射下的脂质过氧化产物。由于胆固醇是细胞膜的主要成分之一，它们可能会发挥影响生物膜硬度的物理化学作用。我们以小鼠成纤维细胞NIH-3T3细胞为真皮模型，研究了异构ChOOHs在不同脂质谱的异质细胞膜中的分布。在血液卟啉存在的UVA照射前后，通过超离心将细胞膜划分为含有较多胆固醇的微结构域（脂筏和小泡）和含有较少胆固醇的非微结构域（含较少胆固醇）。采用二苯基吡啶-薄层色谱印迹分析和气相色谱-电子电离-质谱分析/选择离子监测分析相结合的方法，确定了ChOOH异构体为其三甲基硅氧基衍生物。辐照前发现胆固醇5 α -、7 α -和7 β -氢过氧化物为同分异构体chohs。光照射2 h后，三种ChOOH异构体的数量显著增加。微结构域和非微结构域的choh异构体与胆固醇的比例没有差异，这表明这些choh异构体在两部分的分布是均匀的，取决于胆固醇含量。当细胞用纯化的ChOOH异构体混合物处理时，细胞膜均匀地将ChOOH纳入微结构域和非微结构域。细胞基质金属蛋白酶-9 （MMP-9）活性被纯化的ChOOH异构体混合物处理后提高。这些结果强烈表明，如果真皮细胞暴露于光动力作用下，无论其微观结构如何，ChOOHs都会在细胞膜中积累，并促进MMP活性。2013爱思唯尔爱尔兰有限公司版权所有。
Cholesterol hydroperoxides (ChOOHs) are included as lipid peroxidation products in the skin exposed to ultraviolet (UV) light irradiation. They may exert physicochemical actions affecting biomembrane rigidity because cholesterol is one of the major components of cell membranes. We investigated the distribution of isomeric ChOOHs in heterogeneous cell membranes with different lipid profiles using mouse fibroblast NIH-3T3 cells as a model of the dermis. Before and after UVA irradiation in the presence of hematoporphyrin, cell membranes were partitioned to microdomains (lipid rafts and caveolae) containing a higher amount of cholesterol and non-microdomains (containing a lower amount of cholesterol) by ultracentrifugation. By a combination of diphenylpyrenylphosphine-thin-layer chromatography blotting analyses and gas chromatography-electron ionization-mass spectrometry/selected ion monitoring analyses, ChOOH isomers were determined as their trimethylsilyloxyl derivatives. Cholesterol 5 alpha-, 7 alpha- and 7 beta-hydroperoxide were found as isomeric ChOOHs before irradiation. The amounts of the three ChOOH isomers increased significantly after photoirradiation for 2 h. No difference was observed between microdomains and non-microdomains with regard to the ratio of the amounts of isomeric ChOOHs to that of cholesterol, suggesting that these ChOOH isomers were distributed equally in both parts depending on cholesterol content. When cells were treated with a purified mixture of ChOOH isomers, cell membranes incorporated ChOOHs into microdomains as well as non-microdomains evenly. Cellular matrix metalloproteinase-9 (MMP-9) activity was elevated by treatment with the purified mixture of ChOOH isomers. These results strongly suggest that ChOOHs accumulate in cell membranes irrespective of the heterogeneous microstructure and promote MMP activity if dermal cells are exposed to photodynamic actions. (C) 2013 Elsevier Ireland Ltd. All rights reserved.