Role of microRNA in HIV associated neurological disorder (HAND).

描述(申请人提供)：在过去的十年里，小的非编码RNA分子(~20-30个核苷酸)已经成为真核基因组表达和功能的关键调节因子。这种调节可以发生在基因组功能的几个重要水平上，包括染色质结构、染色体分离、转录、RNA加工、RNA稳定性和翻译。调控的中心主题是，小RNA作为特异性因子，通过碱基配对相互作用指导效应蛋白靶向核酸分子。被广泛研究的小RNA包括小干扰RNAs(SiRNAs)和微RNAs(MiRNAs)。虽然miRNAs被定义为内源基因的调节因子，但siRNAs被描述为基因组完整性的捍卫者，以应对外来或入侵的核酸，如病毒、转座子和转基因。这两类RNA在广泛的真核物种的体细胞谱系中发挥作用。有人提出，病毒感染和疾病结局也可能受到小RNA的影响。这促使我们假设，艾滋病毒感染改变了内源性miRNA的表达模式，从而导致神经元放松调控和艾滋病痴呆。为了支持这一假设，我们开始了研究，以检查病毒蛋白(HIV-1 Tat)对miRNAs表达的影响，因为它具有从感染细胞释放和被不同类型细胞摄取等特征。因此，TAT有可能对感染和未感染的细胞造成损害。有趣的是，使用原代培养的神经元、神经元细胞系、人脑组织和TAT转基因小鼠的大脑，我们的数据显示TAT影响了几个miRNAs(例如miR-34a)及其参与神经元功能的目标基因(例如CREB)的表达，如下面的模型所示。在此基础上，我们建议使用体外和体内动物模型来研究这些受调控的miRNAs以及细胞因素在HIV-1相关神经疾病中的参与。这些研究的结果将有助于预防和/或推迟在艾滋病患者中观察到的神经元放松管制和疾病。

DESCRIPTION (provided by applicant): Over the last decade, small non-coding RNA molecules (~ 20 - 30 nucleotide nt]) have emerged as critical regulators in the expression and function of eukaryotic genomes. The regulation can occur at several important levels of genome function including chromatin structure, chromosome segregation, transcription, RNA processing, RNA stability, and translation. The central theme underlying regulation is that the small RNAs serve as specificity factors that direct effector proteins to target nucleic acid molecules via base-pairing interactions. The categories of small RNAs that have been investigated extensively are the smal interfering RNAs (siRNAs) and microRNAs (miRNAs). While miRNAs have been defined as regulators of endogenous genes, siRNAs are described as defenders of genome integrity in response to foreign or invasive nucleic acids such as viruses, transposons, and transgenes. Both categories of RNAs act in somatic lineages in a broad range of eukaryotic species. It has been suggested that virus infections and disease outcome may also be shaped by small RNAs. This has prompted us to hypothesize that HIV infection alters the endogenous miRNA expression patterns, thereby contributing to neuronal deregulation and AIDS dementia. In support of this hypothesis, we initiated studies to examine the impact of a viral protein (HIV-1 Tat) on miRNAs expression due to its characteristic features such as release from the infected cells and also uptake by diverse cell types. Hence, Tat has the potential to cause damage both in infected and uninfected cells. Interestingly, using primary human cultures of neurons, neuronal cell line, human brain tissues and brains of Tat-transgenic mice, our data show that Tat affected the expression of several miRNAs (e.g. miR-34a) as well as their target genes (e.g. CREB) that are involved in neuronal functions as shown in the model below. Based on that, we propose to investigate the involvement of these regulated miRNAs as well as the cellular factors in the context of HIV-1 associated neurological disease by using in vitro and in vivo animal models. Outcome from these studies will serve to prevent and/or delay neuronal deregulation and disorders observed in AIDS patients.