Aims Interleukin 11 (IL11) was initially thought important for platelet production, which led to recombinant IL11 being developed as a drug to treat thrombocytopenia. IL11 was later found to be redundant for haematopoiesis and its use in patients is associated with unexplained and severe cardiac side effects. Here we aim to identify, for the first time, direct cardiomyocyte toxicities associated with IL11, which was previously believed cardioprotective. Methods and Results We injected recombinant mouse lL11 (rmIL11) into mice and studied its molecular effects in the heart using immunoblotting, qRT-PCR, bulk RNA-seq, single nuclei RNA-seq (snRNA-seq) and ATAC-seq. The physiological impact of IL11 was assessed by echocardiography in vivo and using cardiomyocyte contractility assays in vitro. To determine the activity of IL11 specifically in cardiomyocytes we made two cardiomyocyte-specific Il11ra1 knockout (CMKO) mouse models using either AAV9-mediated and Tnnt2-restricted (vCMKO) or Myh6 (m6CMKO) Cre expression and an Il11ra1 floxed mouse strain. In pharmacologic studies, we studied the effects of JAK/STAT inhibition on rmIL11-induced cardiac toxicities. Injection of rmIL11 caused acute and dose-dependent impairment of left ventricular ejection fraction (saline: 62.4% ± 1.9; rmIL11: 32.6% ± 2.9, p<0.001, n=5). Following rmIL11 injection, myocardial STAT3 and JNK phosphorylation were increased and bulk RNA-seq revealed upregulation of pro-inflammatory pathways (TNFα, NFκB and JAK/STAT) and perturbed calcium handling. snRNA-seq showed rmIL11-induced expression of stress factors (Ankrd1, Ankrd23, Xirp2), activator protein-1 (AP-1) transcription factor genes and Nppb in the cardiomyocyte compartment. Following rmIL11 injection, ATAC-seq identified the Ankrd1 and Nppb genes and loci enriched for stress-responsive, AP-1 transcription factor binding sites. Cardiomyocyte-specific effects were examined in vCMKO and m6CMKO mice, which were both protected from rmIL11-induced left ventricular impairment and molecular pathobiologies. In mechanistic studies, inhibition of JAK/STAT signalling with either ruxolitinib or tofacitinib prevented rmIL11-induced cardiac dysfunction. Conclusions Injection of IL11 directly activates IL11RA/JAK/STAT3 in cardiomyocytes to cause acute heart failure. Our data overturn the earlier assumption that IL11 is cardioprotective and explain the serious cardiac side effects associated with IL11 therapy.

中文翻译：

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白细胞介素 11 疗法可引起急性左心室功能障碍


目的 白细胞介素 11 （IL11） 最初被认为对血小板生成很重要，这导致重组 IL11 被开发为治疗血小板减少症的药物。后来发现 IL11 对于造血是多余的，并且在患者中的使用与无法解释的严重心脏副作用有关。在这里，我们旨在首次确定与 IL11 相关的直接心肌细胞毒性，以前认为 IL11 具有心脏保护作用。方法和结果我们将重组小鼠 lL11 （rmIL11） 注射到小鼠体内，并使用免疫印迹、qRT-PCR、大量 RNA-seq、单核 RNA-seq （snRNA-seq） 和 ATAC-seq 研究其在心脏中的分子效应。通过体内超声心动图和体外心肌细胞收缩测定评估 IL11 的生理影响。为了特异性地确定心肌细胞中 IL11 的活性，我们使用 AAV9 介导和 Tnnt2 限制性 （vCMKO） 或 Myh6 （m6CMKO） Cre 表达和 Il11ra1 絮凝小鼠菌株制作了两个心肌细胞特异性 Il11ra1 敲除 （CMKO） 小鼠模型。在药理学研究中，我们研究了 JAK/STAT 抑制对 rmIL11 诱导的心脏毒性的影响。注射 rmIL11 导致左心室射血分数急性和剂量依赖性损害 （生理盐水：62.4% ± 1.9;rmIL11：32.6% ± 2.9，p<0.001，n=5）。注射 rmIL11 后，心肌 STAT3 和 JNK 磷酸化增加，大量 RNA-seq 显示促炎途径 （TNFα 、 NFκB 和 JAK/STAT） 上调，钙处理受干扰。snRNA-seq 显示 rmIL11 诱导的心肌细胞区室中应激因子 （Ankrd1 、 Ankrd23 、 Xirp2 ）、激活蛋白-1 （AP-1） 转录因子基因和 Nppb 的表达。 注射 rmIL11 后，ATAC-seq 鉴定了 Ankrd1 和 Nppb 基因和基因座，以及富含应激反应性 AP-1 转录因子结合位点的基因座。在 vCMKO 和 m6CMKO 小鼠中检查了心肌细胞特异性影响，它们都受到保护，免受 rmIL11 诱导的左心室损害和分子病理的影响。在机制研究中，ruxolitinib 或 tofacitinib 抑制 JAK/STAT 信号传导可预防 rmIL11 诱导的心功能障碍。结论 注射 IL11 直接激活心肌细胞中的 IL11RA/JAK/STAT3 引起急性心力衰竭。我们的数据推翻了早期 IL11 具有心脏保护作用的假设，并解释了与 IL11 治疗相关的严重心脏副作用。