The Role of RNA Binding Motif 5 in Traumatic Brain Injury

摘要 创伤性脑损伤(TBI)是年轻人死亡和残疾的主要原因。治疗方法是 迫切需要防止细胞死亡，修复神经元连接，并在一年后改善认知结果 TBI。该项目将测试小鼠RNA结合基序5(RBM5)的基因缺失是否会改善分子和 受控皮质撞击(CCI)损伤后的组织学读数和行为结果。 RNA结合蛋白(RBP)调节mRNA的各个方面(例如，RNA剪接、基因表达、 稳定性和细胞定位)。近年来，一些限制性商业惯例被认为与糖尿病的病因有关。 疾病范围从癌症到心血管和神经疾病。RBM5是一种支持死亡的RBP。这个 RBM5诱导细胞死亡的机制包括上调促死亡基因，也通过 调节信使核糖核酸的剪接，从而产生效力更强的有毒蛋白。强制过度表达 癌细胞中RBM5的缺失会导致细胞凋亡、自噬，并阻碍细胞生长。人们对此知之甚少 红细胞膜5在非癌(即正常)细胞和组织中的功能(S)。与中枢神经系统密切相关，我们展示了 小鼠脑外伤后RBM5水平升高。独立于我们的工作，据报道，RBM5水平在 创伤性脊髓损伤。RBM5是否激活了原代中枢神经系统细胞(AS)的细胞死亡尚不清楚 在癌症中是这样的)。我们新的初步数据显示，RBM5在原代培养的大鼠皮质神经元中过表达 增加了他们对随后的机械性拉伤的易感性。这一新发现与我们的 假设(1)RBM5抑制是治疗中枢神经系统损伤的一种有前途的新治疗策略， 和(2)提示RBM5的失调可能介导了基因表达的病理变化 观察到发生在脑外伤后。 在这个项目中，我们肯定会在体内测试RBM5抑制是否具有神经保护作用。新的有条件的 RBM5KO小鼠将受到CCI诱导的损伤。WT与KOS的神经病理学将被检查 伤后1~21d。并于伤后14-21d检测学习记忆功能。此外，我们还将 分析机械拉伸后初级皮质神经元整体基因表达/剪接的变化- 在这种情况下，RBM5水平受到操纵(即通过慢病毒介导的基因敲除与 过度表达)。这项研究代表了对RBM5基因功能的最深入、最大和唯一的分析 到目前为止，人们已经完成了这项研究。

ABSTRACT Traumatic brain injury (TBI) is a leading cause of death and disability in the young. Treatments are desperately needed to prevent cell death, repair neuronal connectivity, and improve cognitive outcomes after a TBI. This project will test if gene deletion of RNA binding motif 5 (RBM5) in mice improves molecular and histological readouts and behavioral outcomes after a controlled cortical impact (CCI) injury. RNA binding proteins (RBPs) regulate all aspects of mRNA (e.g. RNA splicing, gene expression, stability, and cellular localization). In recent years a number of RBPs have been associated with the etiology of disorders ranging from cancer, to cardiovascular and neurological disease. RBM5 is a pro-death RBP. The mechanisms by which RBM5 induces cell death involves upregulation of pro-death genes and also via the modulation of mRNA splicing ,which gives rise to toxic proteins with increased potency. Forced overexpression of RBM5 in cancer cells causes apoptosis, autophagy, and impedes cell growth. Very little is known about the function(s) of RBM5 in non-cancerous (i.e. normal) cells and tissues. Germane to the CNS, we showed that RBM5 levels increase after a TBI in mice. Independent of our work, RBM5 levels also reportedly increase after a traumatic spinal cord injury. It remains to be elucidated if RBM5 activates cell death in primary CNS cells (as it does in cancer). Our new preliminary data show that RBM5 overexpression in primary rat cortical neurons increases their susceptibility to a subsequent mechanical stretch-injury. This new finding is in line with our hypothesis that (1) RBM5 inhibition is a promising new therapeutic strategy for the treatment of CNS injury, and (2) suggests that RBM5 dysregulation may mediate pathological changes in gene expression which has been observed to occur after a TBI. In this project we will definitely test if RBM5 inhibition is neuroprotective in vivo. Novel conditional RBM5 KO mice will be subjected to a CCI induced injury. Neuropathology in WT versus KOs will be examined 1-21d post-injury. Also, learning and memory function will be examined 14-21d post-injury. Additionally we will analyze changes in global gene expression/splicing in primary cortical neurons after a mechanical stretch- injury, and also in which RBM5 levels are manipulated (i.e. by lentivirus mediated knockdown vs. overexpression). This study represents the most in-depth, largest, and only analysis of RBM5 gene function in brain which has been done to date.