Impairment of proteasome function upon UVA- and UVB-irradiation of human keratinocytes
Impairment of proteasome function upon UVA- and UVB-irradiation of human keratinocytes
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DOI：
10.1016/s0891-5849(02)00816-x
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发表时间：
2002-06-01
影响因子：
7.4
通讯作者：
Friguet, B
中科院分区：
文献类型：
--
作者：
Bulteau, AL;Moreau, M;Friguet, B
对表皮细胞的主要环境影响是阳光照射，紫外线辐射对皮肤的有害影响与产生的活性氧物种有关，这些氧物种正在改变细胞成分，包括蛋白质。现已证实，蛋白酶体负责氧化蛋白质的降解。因此，我们研究了紫外线对培养的人角质形成细胞蛋白酶体的影响。用10J/cm2的长波紫外线(UVA)和0.05J/cm2的长波紫外线(UVB)照射人角质形成细胞，用荧光肽测定细胞裂解物中蛋白酶体的活性。三种多肽酶活性均在照射后1h开始下降，持续到24h。在受辐射的细胞中，氧化和泛素化的蛋白质以及被脂质过氧化产物4-羟基-2-壬烯醛修饰的蛋白质水平也增加。然而，免疫纯化的20S蛋白酶体在照射细胞中的肽酶特异性活性和亚基的二维凝胶图谱上没有差异，排除了20S蛋白酶体可能成为紫外线损伤的目标的可能性。最后，经辐射的角质形成细胞的提取物能够抑制蛋白酶体的降解，这表明存在内源性抑制物，包括紫外线照射产生的4-羟基-2-壬烯醛修饰蛋白。(C)2002年爱思唯尔科学公司。
The major environmental influence for epidermal cells is sun exposure and the harmful effect of UV radiation on skin is related to the generation of reactive oxygen species that are altering cellular components including proteins. It is now well established that the proteasome is responsible for the degradation of oxidized proteins. Therefore, the effects of UV-irradiation on proteasome have been investigated in human keratinocyte cultures. Human keratinocytes were irradiated with 10 J/cm(2) of UVA and 0.05 J/cm(2) of UVB and proteasome peptidase activities were measured in cell lysates using fluorogenic peptides. All three peptidase activities were decreased as early as I h and up to 24 h after irradiation of the cells. Increased levels of oxidized and ubiquitinated proteins as well as proteins modified by the lipid peroxidation product 4-hydroxy-2-nonenal were also observed in irradiated cells. However, immunopurified 20S proteasome exhibited no difference in both peptidase specific activities and 2D gel pattern of subunits in irradiated cells, ruling out the possibility that the 20S proteasome could be a target for the UV-induced damage. Finally, extracts from irradiated keratinocytes were able to inhibit degradation by the proteasome, demonstrating the presence of endogeneous inhibitors, including 4-hydroxy-2-nonenal modified proteins, generated upon UV-irradiation. (C) 2002 Elsevier Science Inc.