RNA Therapeutics and Abeta Precursor Protein Translation

描述(申请人提供)：阿尔茨海默氏症淀粉样前体蛋白(APP)，与铁蛋白一样，是一种普遍表达的金属蛋白，在消息翻译水平上受到调节。我们发现，在APP mRNA的稳态水平完全没有变化的情况下，主要的炎症细胞因子白介素1(IL-1)可上调APP的合成，最高可达15倍。IL-1和铁水平显著调节APP-mRNA的翻译(和ABeta肽水平)，与铁调节蛋白(IRPS)和APP 5‘UTR序列(IRE-类型II序列)之间相互作用的变化相关。已知铁内流通过从与APP 5‘UTR序列相关的5’非翻译区特异性RNA茎环中移除IRP来释放翻译抑制中的铁蛋白mRNAs。 了解APP 5‘UTR的调控将使我们能够更好地识别降低APP翻译和Abeta-肽水平的药物化合物。最近已经开发出利用小分子来抑制病毒感染的RNA导向策略，包括针对内部核糖体进入部位丙型肝炎病毒的策略。铁螯合剂去铁胺(Df)(Mw 650)和新型抗胆碱酯酶苯丝氨酸(Ps)(Mw 480)抑制APP 5‘UTR驱动的APP翻译，以减少淀粉样蛋白的输出，例如将该序列用作阿尔茨海默病的治疗靶点。我们将：1.确定顺式作用的IL-1和铁反应的RNA增强子在APP mRNA中的位置和功能作用，并检测5‘UTR和3’UTR序列之间的功能相互作用。2.确定APP 5‘UTR编码的RNA的独特折叠如何为小分子提供治疗靶点，例如去铁胺和抗胆碱酯酶苯丝氨酸。3.验证了改变APP 5中铁调节蛋白(IRP-1和IRP-2)与RNA结构的结合可以介导IL-1信号增加APP翻译的假说。小分子可以通过这一途径很好地作用于减少APP的合成和伴随的ABeta肽的产生。

DESCRIPTION (provided by applicant): The Alzheimer's Amyloid Precursor Protein (APP), like ferritin, is a ubiquitously expressed metaloprotein that is regulated at the level of message translatation. We showed that the primary inflammatory cytokine, Interleukin-1 (IL-1), up-regulated APP synthesis by up to 15-fold in the complete absence of changes to steady-state levels of APP mRNA. IL-1 and iron levels significantly regulate APP-mRNA translation (and ABeta peptide levels) correlated with changed interaction between Iron Regulatory Protein (IRPs) and APP 5'UTR sequences (IRE-Type II sequences). Iron influx is known to release ferritin mRNAs from translational repression by removal of IRP from 5' untranslated region specific RNA stemloops that are related to APP 5'UTR sequences. Understanding regulation conferred by the APP 5'UTR will enable us to better identify medicinal compounds that reduce APP translation and Abeta-peptide levels. RNA-directed strategies have recently been developed for the use of small molecules to suppress viral infections, including a strategy to target the internal ribosome entry site Hepatitis-C virus. The iron chlelator desferrioxamine (Df) (Mw 650) and the novel anticholinesterase, phenserine (Ps) (Mw 480) suppress APP 5'UTR driven translation of APP to reduce amyloid output, exemplifying the use of this sequence as a therapeutic target for Alzheimer's disease. We will: 1. Define the location and functional action of cis-acting IL-1- and iron-responsive RNA enhancers in APP mRNA and examine functional interactions between 5'UTR and 3'UTR sequences. 2. Determine how the unique folding of RNA encoded by the APP 5'UTR offers a therapeutic target for small molecules exemplified by desferrioxamine and the anticholinesterase, phenserine. 3. Test the hypothesis that altering the binding of Iron-regulatory proteins (IRP-1 and IRP-2) to RNA structures in APP 5"UTR mediates IL-1 signals to increase APP translation. Small molecules could well act by this pathway to decrease APP synthesis and concomitant ABeta-peptide output.