State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology (J.Z., M.Z., L.J., P.X., W. Zheng, H.S., Q.H., J. Li, G.C., J. Liu, F.L., X.H., R.-P.X., Yan Zhang), Peking University, Beijing, China.
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering (R.L., X.L.), Peking University, Beijing, China.
Circulation. 2022 Apr 12;145(15):1154-1168. doi: 10.1161/CIRCULATIONAHA.121.055920. Epub 2022 Mar 23.
Cardiac ischemia/reperfusion (I/R) injury has emerged as an important therapeutic target for ischemic heart disease, the leading cause of morbidity and mortality worldwide. At present, there is no effective therapy for reducing cardiac I/R injury. CaMKII (Ca/calmodulin-dependent kinase II) plays a pivotal role in the pathogenesis of severe heart conditions, including I/R injury. Pharmacological inhibition of CaMKII is an important strategy in the protection against myocardial damage and cardiac diseases. To date, there is no drug targeting CaMKII for the clinical therapy of heart disease. Furthermore, at present, there is no selective inhibitor of CaMKII-δ, the major CaMKII isoform in the heart.
A small-molecule kinase inhibitor library and a high-throughput screening system for the kinase activity assay of CaMKII-δ9 (the most abundant CaMKII-δ splice variant in human heart) were used to screen for CaMKII-δ inhibitors. Using cultured neonatal rat ventricular myocytes, human embryonic stem cell-derived cardiomyocytes, and in vivo mouse models, in conjunction with myocardial injury induced by I/R (or hypoxia/reoxygenation) and CaMKII-δ9 overexpression, we sought to investigate the protection of hesperadin against cardiomyocyte death and cardiac diseases. BALB/c nude mice with xenografted tumors of human cancer cells were used to evaluate the in vivo antitumor effect of hesperadin.
Based on the small-molecule kinase inhibitor library and screening system, we found that hesperadin, an Aurora B kinase inhibitor with antitumor activity in vitro, directly bound to CaMKII-δ and specifically blocked its activation in an ATP-competitive manner. Hesperadin functionally ameliorated both I/R- and overexpressed CaMKII-δ9-induced cardiomyocyte death, myocardial damage, and heart failure in both rodents and human embryonic stem cell-derived cardiomyocytes. In addition, in an in vivo BALB/c nude mouse model with xenografted tumors of human cancer cells, hesperadin delayed tumor growth without inducing cardiomyocyte death or cardiac injury.
Here, we identified hesperadin as a specific small-molecule inhibitor of CaMKII-δ with dual functions of cardioprotective and antitumor effects. These findings not only suggest that hesperadin is a promising leading compound for clinical therapy of cardiac I/R injury and heart failure, but also provide a strategy for the joint therapy of cancer and cardiovascular disease caused by anticancer treatment.
心肌缺血/再灌注（I/R）损伤已成为缺血性心脏病这一全球范围内发病率和死亡率首要病因的重要治疗靶点。目前，尚无有效的疗法可减轻心肌 I/R 损伤。CaMKII（钙/钙调蛋白依赖性激酶 II）在包括 I/R 损伤在内的严重心脏疾病的发病机制中发挥关键作用。CaMKII 的药理学抑制是心肌损伤和心脏疾病保护的重要策略。迄今为止，尚无针对心脏疾病的靶向 CaMKII 的药物。此外，目前尚无针对心脏中主要的 CaMKII 同工型 CaMKII-δ 的选择性抑制剂。
我们使用小分子激酶抑制剂文库和 CaMKII-δ9（人心脏中最丰富的 CaMKII-δ 剪接变体）激酶活性测定的高通量筛选系统，筛选 CaMKII-δ 抑制剂。我们结合心肌 I/R（或缺氧/复氧）和 CaMKII-δ9 过表达诱导的心肌细胞损伤，以及在体小鼠模型，利用原代培养的新生大鼠心室肌细胞和人胚胎干细胞衍生的心肌细胞，研究 hesperadin 对心肌细胞死亡和心脏疾病的保护作用。我们还使用人癌细胞异种移植肿瘤的 BALB/c 裸鼠模型，评估 hesperadin 的体内抗肿瘤作用。
基于小分子激酶抑制剂文库和筛选系统，我们发现 hesperadin 是一种体外具有抗肿瘤活性的 Aurora B 激酶抑制剂，可直接与 CaMKII-δ 结合，并以 ATP 竞争性方式特异性阻断其激活。Hesperadin 可改善 I/R 和过表达的 CaMKII-δ9 诱导的心肌细胞死亡、心肌损伤和心力衰竭，在啮齿动物和人胚胎干细胞衍生的心肌细胞中均有此作用。此外，在 BALB/c 裸鼠模型中，人癌细胞异种移植肿瘤模型中，hesperadin 延迟了肿瘤生长，而没有诱导心肌细胞死亡或心脏损伤。
本研究鉴定出 hesperadin 是 CaMKII-δ 的一种特异性小分子抑制剂，具有心脏保护和抗肿瘤的双重作用。这些发现不仅表明 hesperadin 是治疗心肌 I/R 损伤和心力衰竭的有前途的临床候选药物，还为抗癌治疗引起的癌症和心血管疾病的联合治疗提供了策略。
