心脏毒性是化疗药物阿霉素（DOX）的严重副作用。我们最近表明，预诱导自噬减轻了DOX诱导的心肌细胞凋亡和死亡。在这里，我们评估了自噬/线粒体自噬诱导的抗肿瘤药物依维莫司（EVL）对大鼠心肌细胞株H9c2和人类乳腺癌细胞株MCF-7中DOX诱导的细胞毒性的影响。通过使用V荧光素染色法评估细胞凋亡。通过使用荧光测定方法评估自噬和线粒体自噬。通过使用西方印迹法确定细胞蛋白水平。在DOX暴露之前，预处理H9c2细胞使用EVL（1 nM）抑制哺乳动物雷帕霉素靶蛋白（mTOR）活性，诱导自噬和线粒体自噬，以及激活蛋白激酶B（AKT）。在线粒体中，DOX (1 μM)引起了结构性损伤（膜电位降低和细胞色素c释放），增加了超氧化物水平，降低了凋亡抑制蛋白Bcl-2的表达，增加了凋亡诱导蛋白Bax的表达，导致H9c2细胞的凋亡和减少的存活率。EVL预处理抑制了DOX引起的这些变化。使用选择性AKT抑制剂MK-2206处理抑制了EVL的抗凋亡效应。此外，EVL通过自噬/线粒体自噬和AKT激活抑制了DOX诱导的心脏毒性，但不减轻DOX引起的细胞凋亡或存活率降低对MCF-7细胞的影响。总之，EVL可以在不减少DOX抗肿瘤效果的情况下保护心肌细胞免受DOX诱导的凋亡和毒性，从而实现更安全的化疗。©2023年版权归Elsevier Ltd所有。

Cardiotoxicity is a severe side effect of the chemotherapeutic agent doxorubicin (DOX). We recently showed that DOX-induced cardiomyocyte apoptosis and death were attenuated through autophagy pre-induction. Herein, we assessed how the autophagy/mitophagy-inducing antitumor drug everolimus (EVL) affected DOX-induced cytotoxicity in the rat cardiomyocyte cell line H9c2 and human breast cancer cell line MCF-7. Apoptosis was assessed using annexin V assay. Autophagy and mitophagy were assessed using fluorescence assays. Cellular protein levels were determined using western blotting. Pretreatment with EVL (1 nM) before DOX exposure inhibited mammalian target of rapamycin (mTOR) activity, induced autophagy and mitophagy, and activated protein kinase B (AKT) in H9c2 cells. In mitochondria, DOX (1 μM) induced structural damage (decreased membrane potential and release of cytochrome c), increased superoxide levels, decreased apoptosis inhibitor Bcl-2, and increased apoptosis inducer Bax, leading to apoptosis and reduced viability in H9c2 cells. EVL pretreatment suppressed DOX-induced changes. EVL anti-apoptotic effects were inhibited by treatment with MK-2206, a selective AKT inhibitor. Furthermore, EVL suppressed DOX-induced cardiotoxicity through autophagy/mitophagy and AKT activation but did not attenuate DOX-induced apoptosis or reduction in viability in MCF-7 cells. Altogether, EVL can protect cardiomyocytes from DOX-induced apoptosis and toxicity without reducing DOX antitumor effects, allowing safer chemotherapy.Copyright © 2023. Published by Elsevier Ltd.