多柔比星和 Nox2 NADPH 氧化酶诱导的心肌病的信号机制：涉及线粒体融合蛋白-2。

Signalling mechanisms underlying doxorubicin and Nox2 NADPH oxidase-induced cardiomyopathy: involvement of mitofusin-2.

机构信息

Centre for Experimental Medicine, Wellcome-Wolfson Building, Queen's University Belfast, Belfast, UK.

Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK.

出版信息

Br J Pharmacol. 2017 Nov;174(21):3677-3695. doi: 10.1111/bph.13773. Epub 2017 Apr 22.

DOI:10.1111/bph.13773

PMID:28261787

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5647180/

Abstract

BACKGROUND AND PURPOSE

The anthracycline doxorubicin (DOX), although successful as a first-line cancer treatment, induces cardiotoxicity linked with increased production of myocardial ROS, with Nox2 NADPH oxidase-derived superoxide reported to play a key role. The aim of this study was to identify novel mechanisms underlying development of cardiac remodelling/dysfunction further to DOX-stimulated Nox2 activation.

EXPERIMENTAL APPROACH

Nox2 and wild-type (WT) littermate mice were administered DOX (12 mg·kg over 3 weeks) prior to study at 4 weeks. Detailed mechanisms were investigated in murine HL-1 cardiomyocytes, employing a robust model of oxidative stress, gene silencing and pharmacological tools.

KEY RESULTS

DOX-induced cardiac dysfunction, cardiomyocyte remodelling, superoxide production and apoptosis in WT mice were attenuated in Nox2 mice. Transcriptional analysis of left ventricular tissue identified 152 differentially regulated genes (using adjusted P < 0.1) in DOX-treated Nox2 versus WT mice, and network analysis highlighted 'Cell death and survival' as the biological function most significant to the dataset. The mitochondrial membrane protein, mitofusin-2 (Mfn2), appeared as a strong candidate, with increased expression (1.5-fold), confirmed by qPCR (1.3-fold), matching clear published evidence of promotion of cardiomyocyte cell death. In HL-1 cardiomyocytes, targeted siRNA knockdown of Nox2 decreased Mfn2 protein expression, but not vice versa. While inhibition of Nox2 activity along with DOX treatment attenuated its apoptotic and cytotoxic effects, reduced apoptosis after Mfn2 silencing reflected a sustained cytotoxic response and reduced cell viability.

CONCLUSIONS AND IMPLICATIONS

DOX-induced and Nox2-mediated up-regulation of Mfn2, rather than contributing to cardiomyocyte dysfunction through apoptotic pathways, appears to promote a protective mechanism.

LINKED ARTICLES

This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

摘要

背景与目的

蒽环类药物阿霉素（DOX）虽然作为一线癌症治疗药物取得了成功，但会引起心脏毒性，导致心肌 ROS 产生增加，据报道 Nox2 NADPH 氧化酶衍生的超氧阴离子在其中发挥关键作用。本研究旨在确定 DOX 刺激 Nox2 激活后心脏重塑/功能障碍发展的新机制。

实验方法

在研究开始前的 4 周，给予 Nox2 和野生型（WT）同窝仔鼠 DOX（12mg·kg，3 周）。在鼠 HL-1 心肌细胞中，采用强大的氧化应激模型、基因沉默和药理学工具，研究了详细的机制。

主要结果

在 WT 仔鼠中，DOX 诱导的心脏功能障碍、心肌细胞重塑、超氧产生和细胞凋亡在 Nox2 仔鼠中减轻。左心室组织的转录分析确定了 DOX 处理的 Nox2 与 WT 仔鼠相比，有 152 个差异调节基因（调整 P<0.1），网络分析突出了“细胞死亡和存活”是对数据集最重要的生物学功能。线粒体膜蛋白，融合蛋白 2（Mfn2），似乎是一个强有力的候选者，其表达增加（1.5 倍），qPCR 证实（1.3 倍），与促进心肌细胞死亡的明确已发表证据相匹配。在 HL-1 心肌细胞中，Nox2 的靶向 siRNA 敲低降低了 Mfn2 蛋白表达，但反之则不然。虽然 Nox2 活性的抑制以及 DOX 治疗减弱了其凋亡和细胞毒性作用，但 Mfn2 沉默后凋亡减少反映了持续的细胞毒性反应和细胞活力降低。