Aims Interleukin (IL)-12p40 is a common subunit of the bioactive cytokines IL-12 and IL-23, and it also has its own intrinsic functional activity. However, its role in doxorubicin-induced chronic cardiomyopathy (DICCM) as well as the underlying mechanisms are still unknown. Methods and Results In this study, we used IL-12p40-knockout mice, IL-23p19-knockout mice, Rag1-knockout mice, a ferroptosis inhibitor, recombinant IL-12 (rIL-12), rIL-23, rIL-12p40, rIL-12p80, and anti-IL17A to investigate the effects of IL-12p40 on DICCM and elucidate the underlying mechanisms. We found that myocardial ferroptosis were increased in DICCM and that the inhibition of ferroptosis protected against DICCM. The expression of IL-12p40 was upregulated, and IL-12p40 was predominantly expressed by CD4+ T cells in the hearts of mice with DICCM. IL-12p40 knockout attenuated cardiac dysfunction, fibrosis and ferroptosis in DICCM, and similar results were observed in the context of CD4+ T cell IL-12p40 deficiency in Rag1-/- mice. Treatment with rIL-23, but not rIL-12, rIL-12p40 monomer or rIL-12p80, abolished the protective effects of IL-12p40 knockout. Moreover, rIL-23 treatment and IL-23p19 knockout exacerbated and ameliorated DICCM, respectively. IL-12p40 knockout might protect against DICCM by inhibiting Th17 differentiation and IL-17A production but not Th1, Th2 and Treg differentiation. Neutralizing IL-17A with an antibody also attenuated cardiac dysfunction, fibrosis and ferroptosis. The IL-12p40/Th17/IL-17A axis might promote cardiomyocyte ferroptosis by activating TNF receptor-associated factor 6 (TRAF6)/mitogen-activated protein kinase (MAPK)/P53 signaling in DICCM. Conclusions Interleukin-12p40 deficiency protects against DICCM by inhibiting Th17 differentiation and the production of IL-17A, which plays critical roles in cardiomyocyte ferroptosis in DICCM via activating TRAF6/MAPK/P53 signaling. Our study may provide novel insights for the identification of therapeutic targets for treating DICCM in the clinic.

中文翻译：

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白细胞介素 12p40 缺乏症通过抑制 Th17 分化和白细胞介素 17A 的产生来减轻阿霉素诱导的慢性心肌病的心肌铁死亡


目的白细胞介素 （IL）-12p40 是生物活性细胞因子 IL-12 和 IL-23 的常见亚基，也具有自身的内在功能活性。然而，它在阿霉素诱导的慢性心肌病 （DICCM） 中的作用以及潜在机制仍然未知。方法和结果 在本研究中，我们使用 IL-12p40 敲除小鼠、IL-23p19 敲除小鼠、Rag1 敲除小鼠、铁死亡抑制剂、重组 IL-12 （rIL-12）、rIL-23、rIL-12p40、rIL-12p80 和抗 IL17A 来研究 IL-12p40 对 DICCM 的影响并阐明其潜在机制。我们发现 DICCM 中心肌铁死亡增加，并且铁死亡的抑制对 DICCM 具有保护作用。IL-12p40 的表达上调，IL-12p40 主要由 CD4+ T 细胞在 DICCM 小鼠心脏中表达。IL-12p40 敲除减轻了 DICCM 中的心功能不全、纤维化和铁死亡，在 Rag1-/- 小鼠 CD4+ T 细胞 IL-12p40 缺陷的背景下观察到类似的结果。用 rIL-23 而不是 rIL-12、rIL-12p40 单体或 rIL-12p80 处理，消除了 IL-12p40 敲除的保护作用。此外，rIL-23 处理和 IL-23p19 敲除分别加剧和改善了 DICCM。IL-12p40 敲除可能通过抑制 Th17 分化和 IL-17A 的产生而不是 Th1、Th2 和 Treg 分化来预防 DICCM。用抗体中和 IL-17A 还减轻了心功能不全、纤维化和铁死亡。IL-12p40/Th17/IL-17A 轴可能通过激活 DICCM 中的 TNF 受体相关因子 6 （TRAF6）/丝裂原活化蛋白激酶 （MAPK）/P53 信号传导来促进心肌细胞铁死亡。 结论白细胞介素-12p40 缺陷通过抑制 Th17 分化和 IL-17A 的产生来预防 DICCM，IL-17A 通过激活 TRAF6/MAPK/P53 信号传导在 DICCM 心肌细胞铁死亡中起关键作用。我们的研究可能为确定临床治疗 DICCM 的治疗靶点提供新的见解。