Role of oxidative stress in doxorubicin-induced cardiotoxicity racial disparities

非洲裔美国人患阿霉素心脏毒性的风险是白人的3倍。氧化应激是DOX心脏毒性的主要潜在机制，与白人相比，非裔美国人的氧化应激显著加重，这表明氧化应激在DOX心脏毒性的种族差异中发挥了作用。我们的初步数据证实EPHA2.AS1是一个可能调节DOX心脏毒性的新基因。重要的是，EphA2-AS1中的种族特异性SNPs与EphA2表达、钙水平和肝脏炎症标志物的改变有关。EPHA2.AS1位于EPH受体A2(EphA2)的反义链上。EphA2促进线粒体失调和 氧化应激，在多种疾病的发病机制中上调。因此，我们认为，由于氧化应激心脏调节的改变，非裔美国人产生的心脏细胞比美国白人更容易受到DOX诱导的严重心脏毒性，并且EPHA2.AS1调节人类心脏中的EphA2，而EphA2调节心肌线粒体，加剧DOX诱导的心脏毒性。我们将使用一组患者特异性的人类诱导多能干细胞-来自具有和不具有DOX心脏毒性的非裔美国人和白人的心肌细胞来检测ROS的产生，使用我们成熟的生化和功能分析来研究它们对DOX心脏毒性的影响，使用RNA-Seq揭示涉及其种族特异性心脏调节的基因/途径，并在IPSC-心肌细胞和小鼠中筛选心脏保护性抗氧化剂(Aim1)。在ALM2中，我们将定义EPHA2.AS1在线粒体失调驱动的DOX心脏毒性种族差异中的作用。我们将使用CRISPR-Cas9产生的EPHA2.AS1 KO、OE和同基因的IPSC-心肌细胞来评估其对DOX心脏毒性的严重性以及对EphA2调节和信号的影响。此外，我们将使用CRIPSR-Cas9在等基因的IPSC-心肌细胞中引入潜在的候选EPHA2.AS1小种特异性SNPs，随后描述线粒体失调驱动的氧化还原心脏毒性。此外，我们将使用EphA2 KO小鼠来评估EphA2在体内毒副作用中的意义。

African Americans show a 3-fold higher risk of doxorubicin-cardiotoxicity than their White counterparts. Oxidative stress is a major underlying mechanism of dox-cardiotoxicity and is significantly aggravated in African American compared to their white counterparts suggesting a role in dox­ cardiotoxicity racial disparities. Our preliminary data identified EPHA2.AS1 as a novel gene that might regulate dox-cardiotoxicity. Importantly, race-specific SNPs in EPHA2-AS1 are associated with altered EPHA2 expression, calcium levels, and hepatic inflammatory markers. EPHA2.AS1 is located on the antisense strand adjacent to EPH receptor A2 (EPHA2). EPHA2 promotes mitochondrial dysregulation and oxidative stress and is upregulated during the pathogenesis of multiple diseases. Therefore, we hvaothesize that heart cells generated from African Americans are more p_rone to severe dox-induced cardiotoxicity than White Americans due to altered oxidative stress cardiac regulation and that EPHA2.AS1 regulates EPHA2 in the human heart, which dvsregulates cardiac mitochondria, exacerbating dox-induced cardiotoxicity. We will use a cohort of patient-specific human induced pluripotent stem cell-cardiomyocytes derived from African and White Americans with and without dox-cardiotoxicity to examine ROS production, investigate their effect on dox-cardiotoxicity using our well-established biochemical and functional assays, reveal genes/pathways implicating their race-specific cardiac regulation using RNA-Seq, and screen for cardioprotective antioxidants in iPSC-cardiomyocytes and mice (Aim1). In Alm 2, we will define the role of EPHA2.AS1 in mitochondrial dysregulation-driven dox-cardiotoxicity racial disparities. We will use CRISPR-Cas9-generated EPHA2.AS1 KO, OE, and isogenic iPSC-cardiomyocytes to assess its effect on the severity of dox-cardiotoxicity and on EPHA2 regulation and signaling. Furthermore, we will use CRIPSR-Cas9 to introduce potential candidate EPHA2.AS1 race-specific SNPs in isogenic iPSC-cardiomyocytes followed by characterization of mitochondria dysregulation-driven dox-cardiotoxicity. Moreover, we will use an Epha2 KO mouse to assess the implication of Epha2 in dox-cardiotoxicity in vivo.