Suppr超能文献

氧化应激通过激活PKR-eIF2α途径增加β-分泌酶1(BACE1)蛋白水平。

Oxidative stress increases BACE1 protein levels through activation of the PKR-eIF2α pathway.

作者信息

Mouton-Liger François, Paquet Claire, Dumurgier Julien, Bouras Constantin, Pradier Laurent, Gray Françoise, Hugon Jacques

机构信息

Service d'Histologie et de Biologie du Vieillissement, APHP, Groupe Hospitalier Lariboisière Fernand-Widal Saint-Louis, Université Paris VII, Paris, France.

出版信息

Biochim Biophys Acta. 2012 Jun;1822(6):885-96. doi: 10.1016/j.bbadis.2012.01.009. Epub 2012 Jan 28.

Abstract

Beta-site APP cleaving enzyme 1 (BACE1) is the rate limiting enzyme for accumulation of amyloid β (Aβ)-peptide in the brain in Alzheimer's disease (AD). Oxidative stress (OS) that leads to metabolic dysfunction and apoptosis of neurons in AD enhances BACE1 expression and activity. The activation of c-jun N-terminal kinase (JNK) pathway was proposed to explain the BACE1 mRNA increase under OS. However, little is known about the translational control of BACE1 in OS. Recently, a post-transcriptional increase of BACE1 level controlled by phosphorylation of eIF2α (eukaryotic translation initiation factor-2α) have been described after energy deprivation. PKR (double-stranded RNA dependant protein kinase) is a pro-apoptotic kinase that phosphorylates eIF2α and modulates JNK activation in various cellular stresses. We investigated the relations between PKR, eIF2α and BACE1 in AD brains in APP/PS1 knock-in mice and in hydrogen peroxide-induced OS in human neuroblastoma (SH-SY5Y) cell cultures. Immunoblotting results showed that activated PKR (pPKR) and activated eIF2α (peIF2α) and BACE1 levels are increased in AD cortices and BACE1 correlate with phosphorylated eIF2α levels. BACE1 protein levels are increased in response to OS in SH-SY5Y cells and specific inhibitions of PKR-eIF2α attenuate BACE1 protein levels in this model. Our findings provide a new translational regulation of BACE1, under the control of PKR in OS, where eIF2α phosphorylation regulates BACE1 protein expression.

摘要

β-位点淀粉样前体蛋白裂解酶1(BACE1)是阿尔茨海默病(AD)大脑中淀粉样β(Aβ)肽积累的限速酶。导致AD中神经元代谢功能障碍和凋亡的氧化应激(OS)会增强BACE1的表达和活性。有人提出c-jun氨基末端激酶(JNK)通路的激活可以解释OS下BACE1 mRNA的增加。然而,关于OS中BACE1的翻译控制知之甚少。最近,有人描述了能量剥夺后由真核翻译起始因子-2α(eIF2α)磷酸化控制的BACE1水平的转录后增加。PKR(双链RNA依赖性蛋白激酶)是一种促凋亡激酶,可磷酸化eIF2α并在各种细胞应激中调节JNK激活。我们在APP/PS1基因敲入小鼠的AD大脑以及人神经母细胞瘤(SH-SY5Y)细胞培养物中过氧化氢诱导的OS中研究了PKR、eIF2α和BACE1之间的关系。免疫印迹结果显示,AD皮质中活化的PKR(pPKR)、活化的eIF2α(peIF2α)和BACE1水平升高,且BACE1与磷酸化eIF2α水平相关。SH-SY5Y细胞中OS会使BACE1蛋白水平升高,在该模型中PKR-eIF2α的特异性抑制会减弱BACE1蛋白水平。我们的研究结果揭示了在OS中PKR控制下BACE1的一种新的翻译调控机制,即eIF2α磷酸化调节BACE1蛋白表达。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验