SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario
SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario
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DOI：
10.1016/j.bbrc.2015.01.104
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发表时间：
2015-03-06
影响因子：
3.1
通讯作者：
Leopoldino, Andreia M.
中科院分区：
文献类型：
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作者：
Almeida, Luciana O.;Goto, Renata N.;Leopoldino, Andreia M.
我们假设SET是一种在某些癌症类型和阿尔茨海默病中积累的蛋白质，它通过线粒体机制参与细胞死亡。我们用实时定量聚合酶链式反应和免疫荧光方法研究了线粒体解偶联蛋白UCP1、UCP2和UCP3(S和L亚型)的基因和蛋白水平，以及其他线粒体损伤，在有或没有氧化剂叔丁基氢过氧化氢(t-BHP)诱导的氧化应激下过表达SET蛋白(HEK293/SET)。在HEK293细胞中过表达SET降低了UCP1，增加了UCP2和UCP3(S/L)的基因和蛋白水平，同时也防止了脂质过氧化，降低了细胞内三磷酸腺苷的含量。SET过表达还可以(I)减少线粒体的面积，增加细胞器和溶酶体的数量，(Ii)增加线粒体的分裂，表现为FIS1mRNA和FIS-1蛋白水平的增加，DRP-1蛋白的明显积累，VDAC蛋白水平的增加，以及(Iii)自噬通量的减少，如氯喹存在时LC3B脂化作用(LC3B-II)的减少。因此，HEK293细胞中SET的过表达促进了线粒体的分裂，减少了自噬通量，这显然与UCP2和UCP3的上调有关；这意味着可能参与了放松调控的细胞过程，如阿尔茨海默病和癌症。(C)2015 Elsevier Inc.保留所有权利。
We hypothesized that SET, a protein accumulated in some cancer types and Alzheimer disease, is involved in cell death through mitochondrial mechanisms. We addressed the mRNA and protein levels of the mitochondrial uncoupling proteins UCPI, UCP2 and UCP3 (S and L isoforms) by quantitative real-time PCR and immunofluorescence as well as other mitochondrial involvements, in HEK293 cells overexpressing the SET protein (HEK293/SET), either in the presence or absence of oxidative stress induced by the pro-oxidant t-butyl hydroperoxide (t-BHP). SET overexpression in HEK293 cells decreased UCP1 and increased UCP2 and UCP3 (S/L) mRNA and protein levels, whilst also preventing lipid peroxidation and decreasing the content of cellular ATP. SET overexpression also (i) decreased the area of mitochondria and increased the number of organelles and lysosomes, (ii) increased mitochondrial fission, as demonstrated by increased FIS1 mRNA and FIS-1 protein levels, an apparent accumulation of DRP-1 protein, and an increase in the VDAC protein level, and (iii) reduced autophagic flux, as demonstrated by a decrease in LC3B lipidation (LC3B-II) in the presence of chloroquine. Therefore, SET overexpression in HEK293 cells promotes mitochondrial fission and reduces autophagic flux in apparent association with up-regulation of UCP2 and UCP3; this implies a potential involvement in cellular processes that are deregulated such as in Alzheimer's disease and cancer. (C) 2015 Elsevier Inc. All rights reserved.