LncRNA SNHG12, vascular senescence, and atherosclerosis

长非编码RNA(Long Non-Coding RNAs，LncRNAs)作为一种新出现的多种多样的调控因子引起了人们的广泛关注 与动脉粥样硬化相关的生物过程。然而，特定的lncRNA的身份和作用 动脉粥样硬化病变的定义不是很清楚。利用RNA-Seq图谱鉴定特异性衍生的LncRNA 从LDLR-/-小鼠病变进展和消退期的主动脉内膜中，我们鉴定了lncRNA。 小核仁宿主基因12(SNHG12)SNHG12在血管内皮细胞中高度丰富 小鼠、猪和人，随着动脉粥样硬化病变的进展而显著减少，但随着动脉粥样硬化病变的进展而增加。 回归。我们的初步研究表明，GapmeR介导的SNHG12沉默有效地加速了 在LDLR-/-小鼠中，动脉粥样硬化病变的形成超过2倍。值得注意的是，皮损效应的增加是 不是由降脂或皮损白细胞炎性募集所致，而是由DNA增加所致 血管内皮细胞损伤(γH_2AX)和衰老(p16、p21、p27)。积累学习 证明由DNA损伤反应(DDR)引起的血管衰老可能起到不利作用 动脉粥样硬化病变中的慢性炎症。然而，衰老和衰老之间的机制 动脉粥样硬化病变的形成仍然知之甚少。 LncRNAs通过与RNA、染色质修饰物或蛋白质相互作用发挥着重要的调节作用。 编码基因。从机理上讲，使用一种改进的RNA IP(RIP)-MS下拉分析，我们识别 SNHG12与DNA依赖的蛋白激酶(DNA-PK)相互作用控制DNA损伤 回应。初步研究表明，内皮细胞中SNHG12缺乏显著增加了DNA损伤，标志物 衰老和EC对低密度脂蛋白的渗透性。此外，我们还证明了NAD前体烟酰胺 抑制内皮细胞衰老的核糖苷(NR)可能以SNHG12依赖的方式发挥作用。 这些观察结果为中心假说提供了基础，即内皮细胞SNHG12缺乏，通过 对DNA-PK和DNA损伤反应的调节作用，促进血管衰老。 相关的炎症和动脉粥样硬化。为了进一步阐明这一点，提出了三个目标。在Aim1，我们 将阐明SNHG12的S调节DNA-PK介导的DNA损伤反应的分子基础 和血管内皮细胞的衰老。在AIM2中，我们将确定改变lncRNA SNHG12表达的效果 以EC特有的方式对DNA损伤反应和动脉粥样硬化的进展和消退进行研究。在……里面 Aim3，我们将探讨刺激抑制和NR拯救SNHG12的分子机制 在内皮细胞中表达，我们将确定NR的抗衰老作用是否依赖于SNHG12。 这个跨学科的团队在非编码RNA生物学、分子成像、纳米医学、 生物信息学和动脉粥样硬化研究将建立一个前所未有的分子观点的这种lncRNA在 病变可以为调节血管衰老和动脉粥样硬化提供一个新的前沿。

Long non-coding RNAs (lncRNAs) have garnered widespread attention as emerging regulators of diverse biological processes relevant to atherosclerosis. However, the identity and roles of specific lncRNAs within atherosclerotic lesions are not well defined. Using RNA-Seq profiling to identify lncRNAs derived specifically from the aortic intima of LDLR-/- mice during lesion progression and regression phases, we identify the lncRNA Small Nucleolar Host Gene-12 (SNHG12). SNHG12 is highly enriched in the vascular endothelium across mice, pigs, and humans and is significantly reduced with atherosclerotic lesion progression, but increased with regression. Our preliminary studies show that gapmeR-mediated silencing of SNHG12 potently accelerated atherosclerotic lesion formation by over 2-fold in LDLR-/- mice. Remarkably, the increased lesional effects were not driven by lipid-lowering or by inflammatory recruitment of lesional leukocytes, but rather by increased DNA damage (γH2AX) and senescence (p16, p21, p27) in the vascular endothelium. Accumulating studies demonstrate that vascular senescence induced by the DNA damage response (DDR) may adversely contribute to chronic inflammation in atherosclerotic lesions. However, the mechanisms linking senescence and atherosclerotic lesion formation remain poorly understood. LncRNAs play important regulatory roles by interacting with RNA, chromatin modifiers, or protein- coding genes. Mechanistically, using a modified RNA IP (RIP)-mass spectrometry pulldown assay, we identify that SNHG12 interacts with the DNA-dependent protein kinase (DNA-PK) to control the DNA-damage response. Preliminary studies show SNHG12 deficiency in ECs significantly increased DNA damage, markers of senescence, and EC permeability to LDL. Moreover, we demonstrate that the NAD+ precursor nicotinamide riboside (NR), that suppresses endothelial senescence, may function in an SNHG12-dependent manner. These observations provide the foundation for the central hypothesis that endothelial SNHG12 deficiency, via regulatory effects on DNA-PK and the DNA damage response, promotes vascular senescence, senescence- associated inflammation, and atherosclerosis. To elucidate this further, three aims are proposed. In Aim1, we will delineate the molecular basis for SNHG12's ability to regulate DNA-PK-mediated DNA damage response and vascular senescence in ECs. In Aim2, we will determine the effect of altering lncRNA SNHG12 expression in an EC-specific manner on the DNA damage response and atherosclerotic progression and regression. In Aim3, we will explore the molecular mechanisms by which stimuli repress and NR rescues SNHG12 expression in ECs, and we will determine whether the anti-senescent effects of NR are SNHG12-dependent. This multi-disciplinary team in the fields of non-coding RNA biology, molecular imaging, nanomedicine, bioinformatics, and atherosclerosis research will establish an unprecedented molecular view of this lncRNA in lesions that can inform a new frontier in the regulation of vascular senescence and atherosclerosis.