Cardiac fibroblasts constitute the major cell type of the murine and human heart. Once activated, they contribute to an excessive deposition of extracellular matrix (ECM) leading to cardiac fibrosis and subsequently organ dysfunction. With the exception of the pulmonary drugs, nintedanib and pirfenidone, drugs specifically targeting anti-fibrotic pathways are scarce. We recently performed large library screenings of natural occurring compounds and identified first lead structures with anti-fibrotic properties in vitro and in vivo. In line, we now aimed to improve efficacy of these anti-fibrotic lead structures by combining in vitro validation studies and in silico prediction. Next to this combined approach, we performed large OMICs-multi-panel-based mechanistic studies. Applying human cardiac fibroblasts (HCF), we analysed 26 similars of the initially identified anti-fibrotic lead molecules bufalin and lycorine and determined anti-proliferative activity and potential toxicity in an array of in vitro and ex vivo studies. Of note, even at lower concentrations, certain similars were more effective at inhibiting HCF proliferation than nintedanib and pirfenidone. Additionally, selected similars showed low cytotoxicity on human iPS-derived cardiomyocytes and anti-fibrotic gene regulation in human ex vivo living myocardial slices. Further, array and RNA sequencing studies of coding and non-coding RNAs in treated HCFs revealed strong anti-fibrotic properties, especially with the lycorine similar lyco-s (also known as homoharringtonine), that led to a nearly complete shutdown of ECM production at concentrations 100-fold lower than the previously identified anti-fibrotic compound lycorine without inducing cellular toxicity. We thus identified a new natural compound similar with strong anti-fibrotic properties in human cardiac fibroblasts and human living heart tissue potentially opening new anti-fibrotic treatment strategies.

心脏成纤维细胞构成小鼠和人类心脏的主要细胞类型。一旦被激活，它们会导致细胞外基质（ECM）过度沉积，导致心脏纤维化和随后的器官功能障碍。除了肺部药物尼达尼布和吡非尼酮之外，专门针对抗纤维化途径的药物很少。我们最近对天然存在的化合物进行了大型库筛选，并确定了第一个在体外和体内具有抗纤维化特性的先导结构。因此，我们现在的目标是通过结合体外验证研究和计算机预测来提高这些抗纤维化先导结构的功效。除了这种组合方法之外，我们还进行了基于多面板的大型 OMIC 机制研究。应用人心脏成纤维细胞 (HCF)，我们分析了 26 种最初鉴定的抗纤维化先导分子蟾蜍灵和石蒜碱的类似物，并在一系列体外和离体研究中确定了抗增殖活性和潜在毒性。值得注意的是，即使在较低浓度下，某些类似药物在抑制 HCF 增殖方面也比尼达尼布和吡非尼酮更有效。此外，选定的类似物对人 iPS 衍生的心肌细胞显示出低细胞毒性，并且在人离体活心肌切片中显示出抗纤维化基因调节。此外，对处理过的 HCF 中的编码和非编码 RNA 进行的阵列和 RNA 测序研究揭示了强大的抗纤维化特性，特别是与石蒜碱类似的 lyco-s（也称为高三尖杉酯碱），导致 ECM 生产几乎完全停止。其浓度比之前确定的抗纤维化化合物石蒜碱低 100 倍，且不会引起细胞毒性。 因此，我们在人类心脏成纤维细胞和人类活体心脏组织中发现了一种与强抗纤维化特性相似的新天然化合物，有可能开辟新的抗纤维化治疗策略。