Yamada Yu, Sadahiro Taketaro, Nakano Koji, Honda Seiichiro, Abe Yuto, Akiyama Tatsuya, Fujita Ryo, Nakamura Masashi, Maeda Takashi, Kuze Yuta, Onishi Masaya, Seki Masahide, Suzuki Yutaka, Takeuchi Chikara, Iwasaki Yuka W, Murano Kensaku, Sakata-Yanagimoto Mamiko, Chiba Shigeru, Kato Hideyuki, Sakamoto Hiroaki, Hiramatsu Yuji, Ieda Masaki
Department of Cardiology (Y.Y., K.N., S.H., Y.A., T.A., R.F.), University of Tsukuba, Japan.
Department of Cardiology, Keio University School of Medicine (T.S., M.N., T.M., M.I.), Tokyo, Japan.
Circulation. 2025 Feb 11;151(6):379-395. doi: 10.1161/CIRCULATIONAHA.123.067504. Epub 2024 Dec 14.
Heart failure with preserved ejection fraction (HFpEF) is a major health concern. Pathological stimuli and interactions between cardiac fibroblasts (CFs) and other cell types may lead to cardiac fibrosis and diastolic dysfunction, which are hallmarks of HFpEF. Interstitial and perivascular cardiac fibrosis correlates with poor prognosis in HFpEF; however, mechanisms of fibrosis remain poorly elucidated, and targeted therapies are lacking. Cardiac reprogramming is a promising therapeutic approach for myocardial infarction that facilitates cardiac regeneration and antifibrosis action through (MGTH) overexpression in resident CFs. However, the efficacy of this approach on HFpEF is yet to be established.
Herein, we examined the effects of cardiac reprogramming in HFpEF using Tcf21/Tomato/MGTH2A transgenic mice, which expressed both MGTH and reporter expression in CFs for cardiac reprogramming and lineage tracing upon tamoxifen administration. To establish HFpEF model mice, we used a combination of a high-fat diet and nitric oxide synthase inhibition. Bulk RNA-sequencing, single-cell RNA-sequencing, and spatial transcriptomics were conducted to determine fibrotic mechanisms and the efficacy of cardiac reprogramming in HFpEF. We generated new tamoxifen-inducible transgenic mice overexpressing each reprogramming factor in CFs to investigate the effect of single factors. Last, we analyzed the effect of reprogramming factors in human CFs.
Cardiac reprogramming with MGTH overexpression improved diastolic dysfunction, cardiac hypertrophy, fibrosis, inflammation, and capillary loss in HFpEF. Cardiac reprogramming converted approximately 1% of resident CFs into induced cardiomyocytes. Bulk RNA-seq indicated that MGTH overexpression upregulated genes related to heart contraction and suppressed the fetal gene program ( and ) and proinflammatory and fibrotic signatures. Single-cell RNA-sequencing and spatial transcriptomics revealed that multiple CF clusters upregulated fibrotic genes to induce diffuse interstitial fibrosis, whereas distinct CF clusters generated focal perivascular fibrosis in HFpEF. MGTH overexpression reversed these profibrotic changes. Among 4 reprogramming factors, only Gata4 overexpression in CFs reduced fibrosis and improved diastolic dysfunction in HFpEF by suppressing CF activation without generating new induced cardiomyocytes. Gata4 overexpression also suppressed profibrotic signatures in human CFs.
Overexpressing Gata4 in CFs may be a promising therapeutic approach for HFpEF by suppressing fibrosis and improving diastolic dysfunction.
射血分数保留的心力衰竭（HFpEF）是一个主要的健康问题。心脏成纤维细胞（CFs）与其他细胞类型之间的病理刺激和相互作用可能导致心脏纤维化和舒张功能障碍，这是HFpEF的特征。间质和血管周围心脏纤维化与HFpEF的不良预后相关；然而，纤维化的机制仍未得到充分阐明，且缺乏靶向治疗方法。心脏重编程是一种有前景的治疗心肌梗死的方法，通过在驻留CFs中过表达（MGTH）促进心脏再生和抗纤维化作用。然而，这种方法对HFpEF的疗效尚未确定。
在此，我们使用Tcf21/Tomato/MGTH2A转基因小鼠研究了心脏重编程对HFpEF的影响，该转基因小鼠在CFs中同时表达MGTH和报告基因，用于心脏重编程和他莫昔芬给药后的谱系追踪。为建立HFpEF模型小鼠，我们采用了高脂饮食和一氧化氮合酶抑制相结合的方法。进行了批量RNA测序、单细胞RNA测序和空间转录组学分析，以确定HFpEF中的纤维化机制和心脏重编程的疗效。我们构建了新的他莫昔芬诱导型转基因小鼠，使其在CFs中过表达每个重编程因子，以研究单个因子的作用。最后，我们分析了重编程因子对人CFs的影响。
MGTH过表达的心脏重编程改善了HFpEF的舒张功能障碍、心脏肥大、纤维化、炎症和毛细血管丧失。心脏重编程使约1%的驻留CFs转化为诱导型心肌细胞。批量RNA测序表明，MGTH过表达上调了与心脏收缩相关的基因，并抑制了胎儿基因程序（和）以及促炎和纤维化特征。单细胞RNA测序和空间转录组学显示，多个CF簇上调纤维化基因以诱导弥漫性间质纤维化，而不同的CF簇在HFpEF中产生局灶性血管周围纤维化。MGTH过表达逆转了这些促纤维化变化。在4个重编程因子中，只有CFs中Gata4过表达通过抑制CF激活而不产生新的诱导型心肌细胞，减少了HFpEF中的纤维化并改善了舒张功能障碍。Gata4过表达还抑制了人CFs中的促纤维化特征。
在CFs中过表达Gata4可能是一种有前景的治疗HFpEF的方法，可通过抑制纤维化和改善舒张功能障碍来实现。
