Centre for Pharmacology and Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy.
J Transl Med. 2024 Sep 16;22(1):845. doi: 10.1186/s12967-024-05623-8.
Doxorubicin is an important anticancer drug, however, elicits dose-dependently cardiomyopathy. Given its mode of action, i.e. topoisomerase inhibition and DNA damage, we investigated genetic events associated with cardiomyopathy and searched for mechanism-based possibilities to alleviate cardiotoxicity. We treated rats at clinically relevant doses of doxorubicin. Histopathology and transmission electron microscopy (TEM) defined cardiac lesions, and transcriptomics unveiled cardiomyopathy-associated gene regulations. Genomic-footprints revealed critical components of Abl1-p53-signaling, and EMSA-assays evidenced Abl1 DNA-binding activity. Gene reporter assays confirmed Abl1 activity on p53-targets while immunohistochemistry/immunofluorescence microscopy demonstrated Abl1, p53&p73 signaling.
Doxorubicin treatment caused dose-dependently toxic cardiomyopathy, and TEM evidenced damaged mitochondria and myofibrillar disarray. Surviving cardiomyocytes repressed Parkin-1 and Bnip3-mediated mitophagy, stimulated dynamin-1-like dependent mitochondrial fission and induced anti-apoptotic Bag1 signaling. Thus, we observed induced mitochondrial biogenesis. Transcriptomics discovered heterogeneity in cellular responses with minimal overlap between treatments, and the data are highly suggestive for distinct cardiomyocyte (sub)populations which differed in their resilience and reparative capacity. Genome-wide footprints revealed Abl1 and p53 enriched binding sites in doxorubicin-regulated genes, and we confirmed Abl1 DNA-binding activity in EMSA-assays. Extraordinarily, Abl1 signaling differed in the heart with highly significant regulations of Abl1, p53 and p73 in atrial cardiomyocytes. Conversely, in ventricular cardiomyocytes, Abl1 solely-modulated p53-signaling that was BAX transcription-independent. Gene reporter assays established Abl1 cofactor activity for the p53-reporter PG13-luc, and ectopic Abl1 expression stimulated p53-mediated apoptosis.
The tyrosine kinase Abl1 is of critical importance in doxorubicin induced cardiomyopathy, and we propose its inhibition as means to diminish risk of cardiotoxicity.
阿霉素是一种重要的抗癌药物，但会引起剂量依赖性心肌病。鉴于其作用模式，即拓扑异构酶抑制和 DNA 损伤，我们研究了与心肌病相关的遗传事件，并寻找基于机制的可能性来减轻心脏毒性。我们以临床相关剂量的阿霉素治疗大鼠。组织病理学和透射电子显微镜 (TEM) 定义了心脏病变，转录组学揭示了心肌病相关基因调控。基因组足迹揭示了 Abl1-p53 信号的关键组成部分，EMSA 测定证实了 Abl1 的 DNA 结合活性。基因报告基因测定证实了 Abl1 对 p53 靶标的活性，而免疫组织化学/免疫荧光显微镜证实了 Abl1、p53 和 p73 信号。
阿霉素治疗导致剂量依赖性毒性心肌病，TEM 证实了受损的线粒体和肌原纤维排列紊乱。存活的心肌细胞抑制了 Parkin-1 和 Bnip3 介导的线粒体自噬，刺激了 dynamin-1 样依赖性线粒体裂变，并诱导了抗凋亡的 Bag1 信号。因此，我们观察到诱导的线粒体生物发生。转录组学发现细胞反应存在异质性，治疗之间的重叠最小，数据高度提示存在不同的心肌细胞（亚）群，它们在弹性和修复能力上存在差异。全基因组足迹揭示了 Abl1 和 p53 在阿霉素调节基因中富集的结合位点，我们在 EMSA 测定中证实了 Abl1 的 DNA 结合活性。特别地，Abl1 信号在心脏中存在差异，心房心肌细胞中 Abl1、p53 和 p73 的调节具有高度显著性。相反，在心室心肌细胞中，Abl1 仅调节 BAX 转录无关的 p53 信号。基因报告基因测定确定了 Abl1 作为 p53 报告基因 PG13-luc 的共因子活性，异位 Abl1 表达刺激了 p53 介导的凋亡。
酪氨酸激酶 Abl1 在阿霉素诱导的心肌病中具有至关重要的作用，我们提出抑制 Abl1 作为降低心脏毒性风险的一种手段。
