Role of noncoding RNA decay in glucose homeostasis

项目摘要/摘要 RNA的生物发生和衰退的调节对于细胞的动态平衡和失调至关重要 这些过程会导致人类多种发育和代谢紊乱。而转录的 对RNA表达的调控已经得到了广泛的研究，RNA衰变的重要性才刚刚开始 被人欣赏。具体地说，研究非编码RNA(NcRNA)表达的调控和 腐烂由于其大小、丰度、修饰和/或结构造成的限制而受到阻碍 很复杂。我们最近发现了一种3‘到5’外切核糖核酸酶，Dis3l2，它是一个主要的基因。 在核糖核糖核酸的衰变中。在那项研究中，我对Dis3l2底物进行了全球鉴定，发现 大多数Dis3l2靶标是ncRNA。这导致我们确定了Dis3l2介导的衰变 (DMD)作为确保ncRNAs保真度的质量控制途径。人类生殖系突变 Dis3l2基因与帕尔曼综合征有关，帕尔曼综合征是一种罕见但毁灭性的疾病 与早期死亡、低血糖、肾脏异常和胰腺增生有关。这些 提示Dis3l2耗竭患者的ncRNA衰退失调会破坏代谢稳态。 这项研究的主要目的是解开Dis3l2缺陷是如何导致功能受损的 新陈代谢器官的类型尚不清楚。为了了解ncRNA衰变在新陈代谢和 特别是在葡萄糖稳态方面，我计划结合几种创新的方法来研究 利用体外和体内系统研究Dis3l2酶的分子和生理功能。我有过 识别了信号识别粒子(SRP)的7SL RNA组件，SRP是 内质网(ER)介导的翻译，作为Dis3l2的主要底物。我发现在 Dis312缺失，7SL RNA在细胞内聚集并扰乱内质网介导的蛋白 翻译。我们已经建立了Perlman综合征的Dis3l2基因敲除(KO)小鼠模型 表现为人类患者的主要症状，包括围产期死亡，肾脏过度生长， 取消对血糖和胰岛素分泌的调节。此外，Dis3l2耗尽导致 在体外，内质网翻译、内质网钙稳态和胰岛素分泌受损。这证明了一个直接的 Dis3l2在葡萄糖刺激下调节胰岛素分泌中的作用。我将利用Dis3l2 KO 小鼠模型进一步确定内质网介导的蛋白质翻译受损对细胞的影响 和生物体生理学。我的假设是，Dis312耗竭损害了内质网相关的动态平衡 蛋白质翻译是由于异常的7SL RNA积累所致。这项建议具有创新性，因为 Di3l2介导的ncRNA衰变在葡萄糖稳态中的作用以前没有过 据报道。本提案的成功完成对理解 血糖动态平衡，对糖尿病治疗的发展有重大影响。

Project Summary/Abstract Regulation of RNA biogenesis and decay is critical for cellular homeostasis and dysregulation in these processes leads to a variety of human developmental and metabolic disorders. While the transcriptional regulation of RNA expression has been widely studied, the importance of RNA decay is only beginning to be appreciated. Specifically, studying the regulation of noncoding RNA (ncRNA) expression and decay is hampered due to limitations caused by their size, abundance, modifications, and/or structural complexities. We have recently identified a 3’-to-5’ exoribonuclease enzyme, Dis3l2, as a major player in ncRNA decay. In that study, I performed a global identification of Dis3l2 substrates and found that the majority of Dis3l2 targets are ncRNAs. This led to our identification of DIS3L2-Mediated Decay (DMD) as a quality control pathway that ensures the fidelity of ncRNAs. Germline mutations in human DIS3L2 gene have been linked to the Perlman syndrome that is a rare but devastating disorder associated with early lethality, hypoglycemia, kidney abnormalities, and hyperplasia in pancreas. These suggest that dysregulated ncRNA decay in Dis3l2-depleted patients disrupts metabolic homeostasis. The main aim of this research project is to unravel how Dis3l2 deficiency leads to the impaired function of metabolic organs remains unknown. To understand the role of ncRNA decay in metabolism and specially in glucose homeostasis, I plan to combine several innovative approaches to investigate the molecular and physiological functions of Dis3l2 enzyme using in vitro and in vivo systems. I have identified the 7SL RNA component of the signal recognition particle (SRP), a critical player in endoplasmic reticulum (ER)-mediated translation, as a major substrate of Dis3l2. I discovered that in the absence of Dis3l2, aberrant 7SL RNAs accumulate in the cells and perturb ER-mediated protein translation. We have generated a Dis3l2 knockout (KO) mouse model of Perlman syndrome that manifests the main symptoms of human patients including perinatal lethality, kidney overgrowth, abrogated regulation of blood glucose and insulin secretion. Moreover, Dis3l2 depletion caused impaired ER-translation, ER-calcium homeostasis and insulin secretion in vitro. This proves a direct role of Dis3l2 in regulation of insulin secretion in response to glucose stimulation. I will utilize Dis3l2 KO mouse model to further determine the effect of impaired ER-mediated protein translation on cellular and organism physiology. My hypothesis is that Dis3l2 depletion impairs homeostatic ER-associated protein translation due to an accumulation of aberrant 7SL RNAs. This proposal is innovative because the involvement of the Dis3l2-mediated ncRNA decay in glucose homeostasis has not been previously reported. Successful completion of this proposal has broad implications in understanding the basis of glucose homeostasis and have a significant impact on the development of treatments for diabetes.