Dot1L通过Tbx6促进小鼠应激诱导的心脏肥大。

Dot1L Promotes Stress-Induced Cardiac Hypertrophy in Mice via Tbx6.

作者信息

Liu Jiao, Jin Yuxuan, Zuo Shengkai, Mu Chengsen, Wang Bei, Huang Dandan, Liu Qian, Zhang Kai, Song Jiangping, Xuan Chenghao, Zhang Jinying, Yu Ying

机构信息

Department of Pharmacology and Tianjin Key Laboratory of Inflammation Biology, School of Basic Medical Sciences, Tianjin Medical University, China. (J.L., S.Z., C.M., B.W., D.H., Q.L., Y.Y.).

Department of Cardiology, First Affiliated Hospital of Zhengzhou University, China (J.L., Y.J., J.Z., Y.Y.).

出版信息

Circ Res. 2025 Jun 30. doi: 10.1161/CIRCRESAHA.124.324940.

DOI:10.1161/CIRCRESAHA.124.324940

PMID:40583756

Abstract

BACKGROUND

Sustained pathological cardiac hypertrophy eventually leads to heart failure; however, there is currently no effective therapeutic approach. Epigenetic dysregulation, including histone modification alterations, is implicated in cardiac hypertrophy development. Yet, the detailed mechanisms are not completely elucidated.

METHODS

Nano-HPLC-MS/ms was conducted to analyze histone modifications. Cardiomyocyte-specific Dot1L (disruptor of telomeric silencing 1-like) knockout and transgenic mice were generated to evaluate the function of Dot1L in cardiac hypertrophy. Stress was induced in mice by transverse aortic constriction or continuous isoproterenol infusion. RNA-sequencing and chromatin immunoprecipitation sequencing were combined and analyzed to identify the direct transcriptional target of Dot1L, which was verified by multiple molecular biological methodologies. Primary neonatal rat ventricle myocytes were used to identify potential targets and study the molecular mechanisms.

RESULTS

Histone H3K79 dimethylation and its specific methyltransferase Dot1L were upregulated in hypertrophic stimuli-treated cardiomyocytes, cardiac tissues from pressure overload-stressed mice, and patients with hypertrophic cardiomyopathy. The ablation of Dot1L in cardiomyocytes of adult mice protected against pressure overload-induced hypertrophy. Chromatin immunoprecipitation sequencing assay and genome-wide transcriptional analysis showed that Dot1L-catalyzed H3K79 dimethylation promoted the expression of transcription factor Tbx6 in stressed neonatal rat ventricle myocytes. Knockdown of Tbx6 abolished Dot1L overexpression-exaggerated cardiac hypertrophy in mice in response to pressure overload. The Dot1L inhibitor SGC0946 treatment markedly improved isoproterenol-induced cardiac hypertrophy in mice.

CONCLUSIONS

Dot1L-H3K79 dimethylation-Tbx6 axis facilitates pressure overload-induced cardiac hypertrophy. Targeting Dot1L may be a promising therapeutic strategy for heart failure.

摘要

背景

持续性病理性心脏肥大最终会导致心力衰竭；然而，目前尚无有效的治疗方法。表观遗传失调，包括组蛋白修饰改变，与心脏肥大的发展有关。然而，其详细机制尚未完全阐明。

方法

采用纳米高效液相色谱-质谱联用技术分析组蛋白修饰。构建心肌细胞特异性端粒沉默破坏因子1样蛋白（Dot1L）基因敲除和转基因小鼠，以评估Dot1L在心脏肥大中的作用。通过横向主动脉缩窄或持续输注异丙肾上腺素在小鼠中诱导应激。结合并分析RNA测序和染色质免疫沉淀测序，以鉴定Dot1L的直接转录靶点，并通过多种分子生物学方法进行验证。使用原代新生大鼠心室肌细胞来鉴定潜在靶点并研究分子机制。

结果

在经肥大刺激处理的心肌细胞、压力超负荷应激小鼠的心脏组织以及肥厚型心肌病患者中，组蛋白H3K79二甲基化及其特异性甲基转移酶Dot1L上调。成年小鼠心肌细胞中Dot1L的缺失可预防压力超负荷诱导的肥大。染色质免疫沉淀测序分析和全基因组转录分析表明，Dot1L催化的H3K79二甲基化促进了应激的新生大鼠心室肌细胞中转录因子Tbx6的表达。敲低Tbx6可消除Dot1L过表达在压力超负荷情况下加剧的小鼠心脏肥大。Dot1L抑制剂SGC0946治疗可显著改善异丙肾上腺素诱导的小鼠心脏肥大。