Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China.
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
Cell Biol Int. 2020 Sep;44(9):1957-1965. doi: 10.1002/cbin.11374. Epub 2020 Jun 10.
Long noncoding RNAs (lncRNAs) can participate in various biological behaviors, including regulating cell differentiation, proliferation, and apoptosis. The investigators have previously confirmed that highly conserved lncRNA NR_045363 controls cardiomyocyte (CM) proliferation and cardiac repair. The present study investigates the effects of NR_045363 on CM apoptosis. Seven-day-old mice were subjected to permanent left anterior descending coronary artery ligation (LAD), and the NR_045363 expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of NR_045363 in the MI group significantly exceeded the Sham group during the first week after the operation. The NR_045363 expression was knocked down in primary cultured CMs using an NR_045363-targeting lncRNA Smart silencer, and the apoptosis of CMs was analyzed by terminal-deoxynucleoitidyl transferase mediated nick end labeling and Annexin-V/PI double staining. These present results indicate that the NR_045363 knockdown significantly promoted the apoptosis of CMs. In order to investigate the underlying mechanism, RNA-sequencing (RNA-seq) was performed, and ingenuity pathway analysis (IPA) was used to analyze the RNA-seq results. The RNA-seq data revealed that a total of 2,291 genes were upregulated or downregulated in NR_045363 knockdown CMs, and the IPA analysis indicated that tumor protein 53 (p53) was the upstream regulator. In vivo, the NR_045363 overexpression through the AAV9 system improved the heart function after MI in 7-day-old mice and inhibited the CM apoptosis. These data suggest that NR_045363 is involved in CM apoptosis and that NR_045363 overexpression exerts positive effects on cardiac repair by alleviating CM apoptosis through the inhibition of the p53 pathway.
长链非编码 RNA（lncRNA）可以参与多种生物学行为，包括调节细胞分化、增殖和凋亡。研究人员先前已经证实，高度保守的 lncRNA NR_045363 控制心肌细胞（CM）增殖和心脏修复。本研究探讨了 NR_045363 对 CM 凋亡的影响。将 7 日龄小鼠进行永久性左前降支冠状动脉结扎（LAD），通过实时定量聚合酶链反应（qRT-PCR）分析 NR_045363 的表达。在手术后的第一周，MI 组的 NR_045363 表达明显高于 Sham 组。通过 NR_045363 靶向 lncRNA Smart silencer 在原代培养的 CM 中敲低 NR_045363，通过末端脱氧核苷酸转移酶介导的缺口末端标记和 Annexin-V/PI 双染色分析 CM 的凋亡。这些结果表明，NR_045363 的敲低显著促进了 CM 的凋亡。为了探讨潜在的机制，进行了 RNA 测序（RNA-seq），并使用 ingenuity 通路分析（IPA）分析 RNA-seq 结果。RNA-seq 数据显示，NR_045363 敲低的 CM 中共有 2291 个基因上调或下调，IPA 分析表明肿瘤蛋白 53（p53）是上游调节因子。在体内，通过 AAV9 系统过表达 NR_045363 可改善 7 日龄小鼠 MI 后的心脏功能，并抑制 CM 凋亡。这些数据表明，NR_045363 参与 CM 凋亡，NR_045363 过表达通过抑制 p53 通路减轻 CM 凋亡对心脏修复产生积极影响。
