新的人类lncRNA GIVER调控高糖诱导血管平滑肌细胞病变的表观遗传学机制研究

Diabetes mellitus is a major independent risk factor for the development of cardiovascular disease. Recent studies have shown that long non-coding RNAs (lncRNAs) plays pivotal roles on the development of diabetic vasculopathies. However, its molecular mechanisms remain unclear. In our previous studies, we have found several differentially up-regulated novel human lncRNAs in response to high glucose stimulation in vascular smooth muscle cells (VSMCs). Among them, we identified GIVER, a revolutionally conserved lncRNA between human and rat, as a crucial candidate, not only because GIVER interacted with its neighboring gene NR4a3, but also because it modulated the expression of NOX1, Ccl2, et al. Furthermore, IPA analysis revealed that GIVER may be involved in oxidative stress, inflammation, and cell proliferation pathways. In addition, anti-diabetic drug metformin was shown to inhibit GIVER and NR4a3 expression, suggesting that GIVER may be a key regulator in the pathogenesis of diabetic vascular diseases. Accordingly, with our abundant clinical resources and animal samples, we aim to further investigate the molecular characteristics of GIVER, demonstrate the core mechanisms that GIVER regulates diabetic atherogenesis, and explore the potential relationships between metformin treatment and GIVER expression. In summary, by focusing on this novel human lncRNA GIVER, we hope to find novel molecular targets and mechanisms, so as to prevent the development of diabetic vascular diseases.

糖尿病是心血管疾病加速发展的重要独立危险因素。LncRNA在糖尿病血管并发症的形成中发挥了至关重要的调控作用。在预实验中，我们通过测序发现了一个在高糖刺激下表达上调的新的人类lncRNA，将其命名为GIVER。GIVER在人和大鼠中序列相对保守，它不仅与其邻居基因NR4a3相互调控，并有可能通过上调NOX1、Ccl2等分子的转录表达，密切参与血管平滑肌细胞的氧化应激、炎症反应和细胞增殖效应。此外，二甲双胍干预能够显著下调GIVER，强烈提示GIVER可能是糖尿病继发血管并发症的关键调控靶标。因此，本研究将深入研究GIVER的全长分子序列和组织分布特征，阐明GIVER调控糖尿病血管并发症的表观遗传学机制，探索二甲双胍影响GIVER和NR4a3表达的分子机制，并在人类血管标本中验证二者与糖尿病血管并发症之间的相关性，以期发现糖尿病血管并发症的新的分子通路和干预靶标。

糖尿病是心血管疾病加速发展的重要独立危险因素，糖尿病继发心脑血管疾病（如冠心病、脑卒中等）是糖尿病患者致死和致残的主要原因。糖尿病不但严重的影响着糖尿病患者的生活质量，还给国家、社会和家庭带来了沉重的经济负担。究其根本，以血管平滑肌细胞（VSMC）为主血管损伤是重要病理生理机制。因此，阐明糖尿病血管并发症的分子生物学机制，进而提出有效的预警标志和干预策略，是当今医学界亟需解决的科学难题。本研究首先利用大鼠VSMC构建了糖尿病的细胞模型，通过转录组和表观遗传组学研究，发现了397个新的人类长链非编码RNA（lncRNA），其中有13个lncRNA呈差异性表达。随后我们对这些lncRNA周围500kb的邻居基因进行分析，并通过一系列分子生物学手段发现位于5号染色体上的lncRNA165与其邻居基因NR4a3的表达具有密切的时间及空间关系。由于lncRNA165由高糖诱导后在VSMC中特异性表达，因此我们首次将这个新发现的人类lncRNA命名为GIVER（即Glucose-Induced Vsmc-Expressed lncRna）。在此基础上本课题首次发现了人类新基因lncRNA GIVER，并证实它在高血糖、炎症因子、AngII等致病因子的诱导下差异性表达上调。此外，我们还率先证实GIVER在人体标本、动物模型和细胞模型中均参与了高血压继发血管平滑肌损伤。综上所述，本研究发现了心血管疾病的新的潜在干预靶点，有望推动高血压、糖尿病等继发心血管疾病的治疗，具有很好的临床转化应用前景。