Molecular Mechanism of long Noncoding RNAs in Phenylketonuria

研究总结 非编码RNA(LncRNA)在人类遗传病中的作用及分子机制 为建立未来研究方向和治疗的基础提供有前途的新领域 目前缺乏足够治疗选择的疾病的途径。先天代谢紊乱 苯丙酮尿症(PKU)被认为是由苯丙氨酸羟基酶(PAH)突变引起的 基因，导致其酶活性中断，从而在血液中积累苯丙氨酸。 我们的初步数据表明，人的lncRNA HULC与小鼠的lncRNA在功能上是保守的 一对。PKU患者存在HULC基因的基因组变异。对基因敲除会导致色素沉着减退， 生长迟缓、进行性神经症状和癫痫，这些都是人类PKU的忠实模型。 原代人肝细胞中HULC的缺失导致细胞苯丙氨酸升高，提示 HULC/Pair在北京大学的功能重要性。我们定义了HULC和Pair的RNA基序都是积分的 建立lncRNA-酶的相互作用并设计多肽标记的lncRNA模拟物，以恢复 多环芳烃的酶活性。HULC模拟物在PKU小鼠模型中的应用成功缓解过剩 血清中的苯丙氨酸水平，提供了对遗传性疾病基础的机械性洞察。这个 拟议的研究试图建立长的非编码RNA作为启动和进展的重要参与者 并开发基于lncRNA的创新方法来确定新的策略 以解决北京大学的分子基础问题。 中心假设是lncRNA的遗传突变和缺失导致了酶 PAH缺乏，可通过靶向治疗提高蛋白质稳定性和 多环芳烃的酶活性。使用来自PKU患者的iPS分化的肝细胞，我们将首先 通过阐述HULC在北京大学的发展和进展中的生物学意义 常见HULC突变的影响及其与HULC基因突变或缺失的相关性 北大症状。然后我们将阐明lncRNA介导的PAH调节的分子机制。 酶活性。最后，我们将使用富含肝脏的lncRNA模拟物和小分子 激动剂/拮抗剂以确定其在恢复受损的酶功能中的机械作用。 上述研究目的不仅将阐明lncRNAs在代谢紊乱中的作用， 同时也说明了lncRNA模拟物和小分子抑制剂类药物的潜在治疗价值。 在治疗先天遗传病方面。我们预计，这项研究的结果将改变目前的研究和 结合非编码基因的生理和病理方面的临床范例，并为 未来以lncRNA为基础的药物的发展方向。

Research Summary The functional roles and molecular mechanisms of non-coding RNAs (lncRNA) in human genetic disease serve as promising new frontiers for establishing the foundation of future research directions and therapeutic avenues for disorders that currently lack sufficient treatment options. The inborn metabolic disorder phenylketonuria (PKU) has been considered to be caused by mutations in the phenylalanine hydroxylase (PAH) gene, resulting in disruptions to its enzymatic activity and consequent accumulation of phenylalanine in the blood. Our preliminary data demonstrated that the human lncRNA HULC is functionally conserved with mouse lncRNA Pair. PKU patients harbor genomic variants of the HULC gene. Knockout of Pair leads to hypo-pigmentation, growth retardation, progressive neurological symptoms, and seizures, which faithfully models human PKU. Deletion of HULC in primary human hepatocytes leads to elevated cellular Phenylalanine, suggesting the functional importance of HULC/Pair in PKU. We defined the RNA motifs of both HULC and Pair that are integral to establishing lncRNA-enzyme interactions and designed peptide-tagged lncRNA mimics that restored the enzymatic activity of PAH. Administration of HULC mimics in PKU mouse model successfully alleviated excess phenylalanine levels in serum, providing mechanistic insight into the basis of inherited genetic diseases. The proposed study seeks to establish long non-coding RNAs as important players in the initiation and progression of inborn metabolic disorders and develop a lncRNA-based innovative approach for determining new strategies to tackle the molecular basis of PKU. The central hypothesis is that the genetic mutation and deletion of lncRNA results in the enzymatic deficiency of PAH, which could be alleviated through targeting therapies to enhance the protein stability and enzymatic activity of PAH. Using iPS-differentiated hepatocytes derived from PKU patients, we will first demonstrate the biological significance of HULC in the development and progression of PKU by addressing the impact of common HULC mutations and assessing the correlations between mutations or deletions of HULC and PKU symptoms. We will then elucidate the molecular mechanisms of lncRNA-mediated regulation of PAH enzymatic activity. Finally, we will use the administration of liver-enriched lncRNA mimics and small molecule agonists/antagonists to establish their mechanistic role in restoring impaired enzymatic function. The aforementioned research aims will not only elucidate the roles of lncRNAs in metabolic disorders, but also illustrate the potential therapeutic value of lncRNA mimics and small molecule inhibitor-based medicine in treating inborn genetic diseases. We anticipate that the results of this study will shift the current research and clinical paradigm to incorporate the physiological and pathological aspects of non-coding genes and pave the way for the development of future lncRNA-based medicines.