MiR-28 regulates Nrf2 expression through a Keap1-independent mechanism.
MiR-28 regulates Nrf2 expression through a Keap1-independent mechanism.
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DOI：
10.1007/s10549-011-1604-1
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发表时间：
2011-10
影响因子：
3.8
通讯作者：
Zhou, Qun
中科院分区：
文献类型：
--
作者：
Yang, Muhua;Yao, Yuan;Eades, Gabriel;Zhang, Yongshu;Zhou, Qun
核因子-E2相关因子2(NRF2)是一种重要的参与抗氧化反应的转录因子。NRF2与解毒酶(如NAD(P)H-QO1)基因启动子内的抗氧化反应元件(ARE)结合，导致其转录激活。Nrf2的功能受其负调控因子Kelch样ECH相关蛋白1(Keap1)的翻译后调控，KEAP1与Nrf2结合并诱导细胞质Nrf2降解。我们目前的研究提供了新的证据，表明Nrf2的表达可以通过Keap1非依赖的机制来调节。在这里，我们利用乳腺上皮细胞来探索microRNA(MiRNA)对Nrf2表达的影响。我们发现，Nrf2的mRNA水平与miR-28的表达是可逆相关的，而miR-28的异位表达单独降低了Nrf2的mRNA和蛋白水平。我们进一步研究了miR-28抑制Nrf2基因表达的分子机制。首先，通过荧光素酶报告基因检测miR-28对Nrf2基因3‘非翻译区的调控能力。我们观察到miR-28降低了野生型Nrf2 3‘UTR荧光素酶报告基因的活性，当针对Nrf2 3’UTR内的种子序列的miR-28发生突变时，这种抑制作用被消除。此外，miR-28的过表达降低了内源性Nrf2的mRNA和蛋白表达。我们还研究了miR-28对Keap1-Nrf2相互作用的影响，发现miR-28过表达并不改变Keap1的蛋白水平，也不影响Keap1和Nrf2的相互作用。我们的发现，miR-28靶向于Nrf2 mRNA的3‘非编码区，并降低Nrf2的表达，这表明该miRNA参与了乳腺上皮细胞Nrf2的表达调控。
NF-E2-related factor 2 (Nrf2) is an important transcription factor involved in antioxidant response. Nrf2 binds antioxidant response elements (ARE) within promoters of genes encoding detoxification enzymes (e.g., NAD (P) H-quinone oxidoreductase 1 (NQO1)) leading to their transcriptional activation. Nrf2 function is regulated post-translationally by its negative regulator Kelch-like ECH-associated protein 1 (Keap1) that binds Nrf2 and induces cytoplasmic Nrf2 degradation. Our present studies provide new evidence that Nrf2 expression can be regulated by a Keap1-independent mechanism. Here, we utilized breast epithelial cells to explore the impact of microRNA (miRNA) on Nrf2 expression. We found that Nrf2 mRNA levels are reversibly correlated with miR-28 expression and that ectopic expression of miR-28 alone reduces Nrf2 mRNA and protein levels. We further investigated the molecular mechanisms by which miR-28 inhibits Nrf2 mRNA expression. Initially, the ability of miR-28 to regulate the 3′ untranslated region (3′UTR) of Nrf2 mRNA was evaluated via luciferase reporter assay. We observed that miR-28 reduces wild-type Nrf2 3′UTR luciferase reporter activity and this repression is eliminated upon mutation of the miR-28 targeting seed sequence within the Nrf2 3′UTR. Moreover, over-expression of miR-28 decreased endogenous Nrf2 mRNA and protein expression. We also explored the impact of miR-28 on Keap1-Nrf2 interactions and found that miR-28 overexpression does not alter Keap1 protein levels and has no effect on the interaction of Keap1 and Nrf2. Our findings, that miR-28 targets the 3′UTR of Nrf2 mRNA and decreases Nrf2 expression, suggest that this miRNA is involved in the regulation of Nrf2 expression in breast epithelial cells.
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影响因子：
3.8
作者：
Niture SK;Kaspar JW;Shen J;Jaiswal AK
通讯作者：
Jaiswal AK
影响因子：
--
作者：
Acharya A;Das I;Chandhok D;Saha T
通讯作者：
Saha T
影响因子：
5.3
作者：
Havens, Courtney G.;Ho, Alan;Dowdy, Steven F.
通讯作者：
Dowdy, Steven F.
DOI：
10.1073/pnas.172398899
发表时间：
2002-09-03
影响因子：
11.1
作者：
Dinkova-Kostova, AT;Holtzclaw, WD;Talalay, P
通讯作者：
Talalay, P
影响因子：
20.3
作者：
Girardot, Michael;Pecquet, Christian;Constantinescu, Stefan N.
通讯作者：
Constantinescu, Stefan N.