The mRNA splicing factor RBM5: A new therapeutic target for TBI

mRNA剪接因子RBM5：TBI的新治疗靶点

基本信息

批准号：
8845278
负责人：
TRAVIS C JACKSON
金额：
$ 23.1万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-07-01 至 2016-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8845278
关键词：
Acute Brain Injuries Anthraquinones Apoptotic Applications Grants Behavioral Brain Brain Diseases Brain Injuries CASP8 and FADD-like apoptosis regulating protein CASP8 gene Caspase Cause of Death Cell Death Cells Cellular Stress Cessation of life Clinical Trials Cognitive Data Drosophila pros protein Drug Targeting Enhancers Enzymes Excision Exclusion Exons Genes Health Hippocampus (Brain)Human Hydrogen Peroxide Impairment In Vitro Injury Intervention Introns Knowledge Learning Length Lesion Mechanics Mediating Memory Messenger RNA Modeling Mus Neurons Nuclear Nuclear Proteins Pharmaceutical Preparations Play Population Process Protein Isoforms Protein Splicing Proteins Publications RNA Binding RNA Recognition Motif RNA Splicing Rattus Recovery Reporting Role Site Spliceosome Assembly Pathway Spliceosomes Staurosporine Stretching Structure Sulfonic Acids TNF gene TNFSF10 gene TNFSF6 gene Testing Testis Therapeutic Toxic effect Transcript Traumatic Brain Injury Up-Regulation Variant Zinc Fingers cancer cell caspase-2 central nervous system injury controlled cortical impact disability in vitro testing in vivo inhibitor/antagonist injured intravenous administration mRNA Expression mRNA Precursor new therapeutic target novel overexpression pro-caspase-2 protein B protein expression response small molecule social

项目摘要

DESCRIPTION (provided by applicant): Reports estimate that over 90% of all human genes are subject to mRNA splicing. RNA splicing occurs in highly specialized structures termed nuclear spliceosomes. Spliceosomes consist of a few key proteins that catalyze the excision of target introns/exons, plus 100's of co-factors that regulate the activity/efficiency of these enzymes. Spliceosome co-factors direct many facets of splicing dynamics including distribution of different protein variants throughout the body. Brain injury and disease disturb splicing. Pathological changes in spliceosome mechanics alter splice variant expression of different survival and death proteins. An upregulation of maladaptive protein variants may exacerbate neuronal death and impair CNS recovery. RNA Binding Motif 5 (RBM5) is a splicing co-factor. It is highly expressed in the CNS and testis but its function in the healthy or injured brain is unknown. RBM5 briefly localizes to the spliceosome, very early during spliceosome assembly around pre-mRNA targets. A zinc finger domain (RanBP2-Type), and several other RNA binding domains, coordinate its highly selective interaction with spliceable exons in pre-mRNA targets. In cancer cells, RBM5 regulates splice variant selection of caspase-2 (pro-death) and c-FLIP (pro-survival) genes. It promotes the exclusion of exon 9 from caspase-2, and exon 7 from c-FLIP mRNA. This induces caspase2L and c-FLIPL protein expression, respectively. Caspase2L is a pro-death splice variant. The c-FLIPL splice variant also has pro-apoptotic functions. In contrast, RBM5 inhibition causes exon 9/7 retention, respectively, and forces caspase-2s/c-FLIPs expression. Caspase-2s and c-FLIPs are both potent pro-survival variants. Thus RBM5 promotes cell death by upregulating the ratio of pro-death to pro-survival splice variants. RBM5 has not been studied in the brain. High expression in the CNS suggests that it may play a key role in splicing-mediated cell death mechanisms. To the best of our knowledge, no drug has ever been developed to specifically target pro-death splicing mechanisms in the brain - thus the therapeutic value of splicing directed therapies is completely unknown. Our preliminary data show that RBM5 is highly enriched in the hippocampal CA3 formation - a neuron population that is especially vulnerable to traumatic brain injury (TBI). Furthermore, we show that anthraquinone-2-sulfonic acid (AQ2S), the world's first small-molecule RBM5 inhibitor (that blocks the RanBP2-Type domain), decreases neuronal death after TBI in vitro and in vivo. This grant proposal seeks to test our hypothesis that RBM5 is a potent pro-death splicing factor in rat/human neurons (i.e. show that it upregulates caspase-2L and c-FLIPL splicing in these cells), and further confirm our preliminary data showing that AQ2S is the first viable drug to block pro-death splicing mechanisms in the brain.

描述（由申请人提供）：报告估计，所有人类基因中有90％以上受mRNA剪接的约束。 RNA剪接发生在称为核剪接体的高度专业结构中。剪接体由一些关键蛋白组成，这些蛋白质可催化目标内含子/外显子的切除，再加上100个co因子，这些蛋白会调节这些酶的活性/效率。剪接体的辅助因子指导剪接动力学的许多方面，包括在整个体内的不同蛋白质变体的分布。脑损伤和疾病干扰剪接。剪接体力学的病理变化改变了不同生存和死亡蛋白的剪接变异表达。适应不良蛋白质变异的上调可能加剧神经元死亡并损害CNS恢复。 RNA结合基序5（RBM5）是拼接的共同因素。它在中枢神经系统和睾丸中高度表达，但其在健康或受伤的大脑中的功能尚不清楚。 RBM5在剪接体组装前围绕MRNA靶标的剪接组组件的早期就将其简要定位于剪接体。锌指域（RANBP2型）和其他几个RNA结合结构域，将其高度选择性相互作用与前MRNA靶标的可剪接外显子协调。在癌细胞中，RBM5调节CASPASE-2（亲死亡）和C-FLIP（亲苏属）基因的剪接变异选择。它促进了从caspase-2中排除外显子9，而从c-Flip mRNA中促进了外显子7。这分别诱导caspase2L和C-FLIPL蛋白表达。 caspase2l是一种亲死亡的剪接变体。 C-FLIPL剪接变体还具有促凋亡功能。相反，RBM5抑制分别导致外显子9/7保留，并迫使caspase-2s/c-Flips表达。 caspase-2s和c-Flips都是有效的亲寿命变体。因此，RBM5通过上调亲死亡与临床剪接变体的比率来促进细胞死亡。 RBM5尚未在大脑中研究。中枢神经系统中的高表达表明，它可能在剪接介导的细胞死亡机制中起关键作用。据我们所知，尚未开发出任何药物来专门针对大脑中的亲死亡剪接机制 - 因此，剪接定向疗法的治疗价值是完全未知的。我们的初步数据表明，RBM5在海马CA3形成中高度富集 - 一种神经元群体特别容易受到创伤性脑损伤（TBI）。此外，我们表明世界上第一个小分子RBM5抑制剂（阻断RANBP2型型结构域）蒽醌-2-磺酸（AQ2S）降低了TBI Interro和In Vivo后的神经元死亡。该赠款提案旨在检验我们的假设，即RBM5是大鼠/人类神经元中有效的亲死亡剪接因子（即表明它上调了这些细胞中的caspase-2L和C-FLIPL剪接），并进一步证实了我们的初步数据，表明我们是第一个可行的AQ2药物来阻止Pro Depon Dephephephephephephephephephepheplicing机械机构。