Role of snoRNAs in regulation of cardiac hypertrophy

摘要 病理性心肌肥大是许多心血管疾病的共同特征，如高血压， 主动脉瓣狭窄、缺血性心脏病和心力衰竭。因此，心肌细胞肥大的调节 已经得到了广泛的研究，它在一定程度上受到活性氧物种(ROS)的调节。尽管如此，还有 一直没有成功的临床治疗方法专门针对ROS或心血管氧化应激作为一种 病理机制。 这项建议的目的是研究一种新的和药物靶向的途径，调节ROS和 氧化应激通过非编码RNA(NcRNA)，称为snoRNA(小核仁RNA)。这些短的ncRNA 典型地充当催化靶RNA上的核苷酸修饰的酶的“向导”。最近，有四个 来自Rpl13a基因座的snoRNAs已被确定为ROS和氧化应激的意外调节因子， 在体外和体内都有。 由于心肌肥厚是由ROS调节的，我们假设Rpl13a snoRNAs将是重要的 在这个过程中。现在的初步数据显示，缺乏Rpl13a snoRNAs的小鼠实际上对 横主动脉压力超负荷状态下的肥厚和病理性心脏重构 收缩。此外，这些snoRNA的缺失也会导致幼鼠心脏异常小， 提示Rpl13a snoRNAs可能是心肌细胞大小的一般调节因子。这项研究建议 将建立在这些重要的生理学发现的基础上，以便通过 Rpl13a snoRNA影响ROS、氧化应激和心肌细胞大小。具体地说，目标一号将 利用体外和体外实验，识别和验证受Rpl13a snoRNAs调控的转录网络 心肌细胞肥大的活体模型结合RNA-SEQ定量评估编码和 非编码RNA。AIM 2将专门研究NOX4和Rpl13a snoRNAs之间的关系 ROS介导的对心肌细胞大小的调节，用于测定正常细胞大小和 肥大。这里生成的初步数据将用于支持更大的R01应用程序直接 阐述snoRNAs调节ROS和氧化应激与心肌细胞大小的机制 和肥大。

ABSTRACT Pathologic cardiac hypertrophy is a common feature in many cardiovascular diseases, such as hypertension, aortic stenosis, ischemic heart disease, and heart failure. As such, the regulation of cardiomyocyte hypertrophy has been extensively studied, and it is regulated, in part, by reactive oxygen species (ROS). Despite this, there have been no successful clinical treatments that specifically target ROS or cardiovascular oxidative stress as a pathologic mechanism. The aim of this proposal is to investigate a novel and drug-targetable pathway that regulates ROS and oxidative stress via non-coding RNAs (ncRNA) known as snoRNA (small nucleolar RNA). These short ncRNA canonically act as “guides” for enzymes that catalyze nucleotide modifications on target RNAs. Recently, four snoRNAs from the Rpl13a locus have been identified as unexpected regulators of ROS and oxidative stress, both in vitro and in vivo. Since cardiac hypertrophy is regulated by ROS, we hypothesized that the Rpl13a snoRNAs would be important for this process. Preliminary data now shows that mice lacking the Rpl13a snoRNAs are, in fact, resistant to hypertrophy and pathologic cardiac remodeling in the setting of pressure overload from transverse aortic constriction. Moreover, the loss of these snoRNAs also results in unusually small hearts in young mice, suggesting that the Rpl13a snoRNAs may be general regulators of cardiomyocte size. The research proposed in this application will build on these important physiologic findings in order to understand the mechanisms by which the Rpl13a snoRNAs influence ROS, oxidative stress, and cardiac cell size. Specifically, Aim 1 will identify and validate transcriptional networks that are regulated by the Rpl13a snoRNAs, using in vitro and in vivo models of cardiomyocyte hypertrophy combined with RNA-seq to quantitatively assess both coding and non-coding RNAs. Aim 2 will specifically examine the relationship between Nox4 and the Rpl13a snoRNAs in the ROS-mediated regulation of cardiomyocyte size, both for the determination of normal cell size and hypertrophy. The preliminary data generated here will be used to support a larger R01 application to directly address the mechanisms by which snoRNAs regulate ROS and oxidative stress in relation to cardiac cell size and hypertrophy.