Novel long non-coding RNAs are involved in cellular response to angiotensin II signaling

Angiotensin II (AngII) is a polypeptide hormone that plays a pivotal role in the regulation of blood pressure. In vascular smooth muscle cells (VSMCs), AngII signaling results in hypertrophy, proliferation, contraction, and migration, which ultimately promote atherosclerosis and hypertensive cardiovascular diseases. Recent studies have shown that fundamental biological processes such as cell proliferation and differentiation are mediated in part by the activities of long non-protein-coding RNAs (lncRNAs). In this study, we sought to identify lncRNAs that are involved in the response to AngII-signaling. Genome-wide analysis of de novo assembled transcripts from rat vascular smooth muscle cells (VSMCs) identified novel lncRNA as well as protein-coding transcripts which have not been previously annotated. The majority of the genomic loci from which these novel transcripts are transcribed are enriched for histone H3 lysine 4 trimethylation and histone H3 lysine 36 trimethylation, two chromatin modifications that are closely associated with actively transcribed regions, further supporting these as bona fide transcripts. Compared with previously annotated rat transcripts, these novel lncRNA transcripts, on average, are shorter in length and are less abundant, consistent with reports from mice and humans. Expression analyses of transcripts from control and AngII-stimulated VSMCs reveal that AngII signaling affects the abundance of both protein-coding transcripts as well as lncRNAs transcripts. Altogether, these data provide new insights into the global effects of AngII signaling and reveal potential novel therapeutic targets for treatment of AngII-associated cardiovascular diseases. Overall design: RNA-sequencing of control and AngII (3hrs)-stimulated rVSMSCs. ChIP-sequencing of H3K4me3 and H3K36me3 in control and AngII (3hrs)-stimulated rVSMCs.

血管紧张素II（Angiotensin II, AngII）是一种在血压调控中发挥关键作用的多肽激素。在血管平滑肌细胞（vascular smooth muscle cells, VSMCs）中，AngII信号通路可引发细胞肥大、增殖、收缩与迁移，最终促进动脉粥样硬化与高血压性心血管疾病的发生发展。近期研究表明，细胞增殖与分化等核心生物学过程，部分由长链非编码RNA（long non-protein-coding RNAs, lncRNAs）的活性所介导。本研究旨在筛选参与AngII信号通路应答的lncRNAs。我们对大鼠血管平滑肌细胞的从头组装转录本开展全基因组分析，鉴定出了此前未被注释的新型lncRNA与编码蛋白的转录本。这些新型转录本的转录基因组位点，大多富集组蛋白H3赖氨酸4三甲基化（H3K4me3）与组蛋白H3赖氨酸36三甲基化（H3K36me3）这两种与活跃转录区域紧密相关的染色质修饰，进一步证实它们属于真实存在的转录本。相较于此前已注释的大鼠转录本，这些新型lncRNA转录本平均长度更短、表达丰度更低，这与小鼠和人类中的相关研究结果一致。对对照组与AngII刺激的血管平滑肌细胞的转录本进行表达分析后发现，AngII信号通路可同时影响编码蛋白转录本与lncRNA的表达丰度。综上，本研究数据为AngII信号通路的全局调控效应提供了新见解，并揭示了治疗AngII相关心血管疾病的潜在新型治疗靶点。整体实验设计：对对照组与AngII（刺激3小时）处理的大鼠血管平滑肌细胞开展RNA测序（RNA-sequencing）；对对照组与AngII（刺激3小时）处理的大鼠血管平滑肌细胞开展H3K4me3与H3K36me3的染色质免疫共沉淀测序（ChIP-sequencing）。