State Key Laboratory of Proteomics, Collaborative Innovation Center for Cardiovascular Disorders, Genetic Laboratory of Development and Disease, Institute of Biotechnology, 20 Dongdajie, Beijing 100071, China.
Institute of Vascular Medicine, Peking University Third Hospital and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, 49 Huayuan-Bei Road, Beijing 100191, China.
Cardiovasc Res. 2016 Jul 1;111(1):56-65. doi: 10.1093/cvr/cvw078. Epub 2016 Apr 15.
The H19 lncRNA, a highly abundant and conserved imprinted gene, has been implicated in many essential biological processes and diseases. However, the function of H19 in the heart remains unknown. In this study, we investigated the function and underlying mechanism of H19 in regulating cardiomyocyte hypertrophy.
We first detected the expression of H19 and its encoded miR-675 in both normal and diseased hearts and verified their up-regulations in pathological cardiac hypertrophy and heart failure. Adenovirus-mediated expression and a siRNA-mediated silence of H19 showed that H19 overexpression reduced cell size both at baseline and in response to phenylephrine, whereas knock-down of H19 induced cardiomyocyte hypertrophy. Overexpression or knock-down of miR-675 in cardiomyocytes demonstrated that miR-675 also inhibited cardiomyocyte hypertrophy. Moreover, inhibition of miR-675 reversed the reduction of cardiomyocyte size in H19-overexpressing cardiomyocytes, while infection with an adenovirus carrying H19 fragment without pre-miR-675 (H19-Tru) or with mutant sequences of pre-miR-675 (H19-Mut) failed to reduce cardiomyocyte size, indicating that miR-675 mediated the inhibitory effect of H19 on cardiomyocyte hypertrophy. We also identified that CaMKIIδ was a direct target of miR-675 and partially mediated the effect of H19 on cardiomyocyte hypertrophy. Furthermore, in vivo silencing of miR-675 using a specific antagomir in a pressure overload-induced mouse model of heart failure increased cardiac CaMKIIδ expression and exacerbated cardiac hypertrophy.
These findings reveal a novel function of H19-miR-675 axis targeting CaMKIIδ as a negative regulator of cardiac hypertrophy, suggesting its potential therapeutic role in cardiac diseases.
H19 lncRNA 是一种高度丰富且保守的印记基因，与许多重要的生物学过程和疾病有关。然而，H19 在心脏中的功能尚不清楚。在这项研究中，我们研究了 H19 调节心肌细胞肥大的功能和潜在机制。
我们首先检测了正常和患病心脏中 H19 及其编码的 miR-675 的表达，并证实它们在病理性心肌肥大和心力衰竭中上调。腺病毒介导的 H19 表达和 siRNA 介导的 H19 沉默表明，H19 过表达减少了基础状态和苯肾上腺素反应时的细胞大小，而 H19 敲低则诱导了心肌细胞肥大。miR-675 在心肌细胞中的过表达或敲低表明，miR-675 也抑制了心肌细胞肥大。此外，抑制 miR-675 逆转了 H19 过表达心肌细胞中心肌细胞大小的减少，而感染不含 pre-miR-675 的 H19 片段（H19-Tru）或具有 pre-miR-675 突变序列的腺病毒（H19-Mut）则不能减少心肌细胞大小，表明 miR-675 介导了 H19 对心肌细胞肥大的抑制作用。我们还发现 CaMKIIδ 是 miR-675 的直接靶标，并部分介导了 H19 对心肌细胞肥大的作用。此外，在压力超负荷诱导的心力衰竭小鼠模型中，使用特异性反义寡核苷酸抑制 miR-675 可增加心脏 CaMKIIδ 的表达并加剧心肌肥大。
这些发现揭示了 H19-miR-675 轴靶向 CaMKIIδ 作为心肌肥大负调节剂的新功能，提示其在心脑血管疾病治疗中的潜在作用。
