心肌细胞DNA修复机制丧失引发扩张型心肌病

Loss of DNA repair mechanisms in cardiac myocytes induce dilated cardiomyopathy

AGING CELL

影响因子:7.1

分区:医学1区 Top / 老年医学1区细胞生物学2区

发表日期:2023 Apr

作者: Chathurika Henpita, Rajesh Vyas, Chastity L Healy, Tra L Kieu, Aditi U Gurkar, Matthew J Yousefzadeh, Yuxiang Cui, Aiping Lu, Luise A Angelini, Ryan D O'Kelly, Sara J McGowan, Sanjay Chandrasekhar, Rebecca R Vanderpool, Danielle Hennessy-Wack, Mark A Ross, Timothy N Bachman, Charles McTiernan, Smitha P S Pillai, Warren Ladiges, Mitra Lavasani, Johnny Huard, Donna Beer-Stolz, Claudette M St Croix, Simon C Watkins, Paul D Robbins, Ana L Mora, Eric E Kelley, Yinsheng Wang, Timothy D O'Connell, Laura J Niedernhofer

DOI: 10.1111/acel.13782

摘要

心肌病是一种逐渐发展的心肌疾病，导致心肌收缩功能障碍。已知基因毒性癌症治疗是心肌病的强烈驱动因素，而自发性疾病的原因尚不清楚。为验证内源性基因毒性应激是否促发心肌病，我们利用带有Ercc1 floxed等位基因的突变鼠以及在肌肉特异性肌酐激酶（Ckmm）启动子控制下表达Cre的鼠，或系统性缺失Ercc1（Ercc1-/D）模型，特异性删除了Ercc1基因。Ckmm-Cre+/- ;Ercc1-/fl小鼠在7个月大时因心脏疾病猝死。作为年轻成年鼠，Ckmm-Cre+/- ;Ercc1-/fl的心脏在结构和功能上均正常，但到6个月时，出现明显的心室扩张、心壁变薄、间质纤维化和收缩功能障碍，表现为扩张型心肌病。组织特异性或系统性模型的心脏组织显示出凋亡增加，Ckmm-Cre+/- ;Ercc1-/fl的心肌细胞对基因毒素表现出超敏反应，导致细胞凋亡。p53水平及其靶基因表达（包括几种抗氧化剂）在Ckmm-Cre+/- ;Ercc1-/fl和Ercc1-/D模型中均升高。尽管如此，老年突变鼠的心脏组织仍显示出氧化应激增强的证据。基因或药理学抑制p53能减轻凋亡并改善疾病指标。类似地，线粒体靶向过表达过氧化氢酶也改善了疾病表现。这些数据支持内源性DNA损伤可以驱动心脏疾病，其机制通过p53的慢性激活及氧化应激的增加，促使心肌细胞凋亡、扩张型心肌病及猝死。

Abstract

Cardiomyopathy is a progressive disease of the myocardium leading to impaired contractility. Genotoxic cancer therapies are known to be potent drivers of cardiomyopathy, whereas causes of spontaneous disease remain unclear. To test the hypothesis that endogenous genotoxic stress contributes to cardiomyopathy, we deleted the DNA repair gene Ercc1 specifically in striated muscle using a floxed allele of Ercc1 and mice expressing Cre under control of the muscle-specific creatinine kinase (Ckmm) promoter or depleted systemically (Ercc1-/D mice). Ckmm-Cre+/- ;Ercc1-/fl mice expired suddenly of heart disease by 7 months of age. As young adults, the hearts of Ckmm-Cre+/- ;Ercc1-/fl mice were structurally and functionally normal, but by 6-months-of-age, there was significant ventricular dilation, wall thinning, interstitial fibrosis, and systolic dysfunction indicative of dilated cardiomyopathy. Cardiac tissue from the tissue-specific or systemic model showed increased apoptosis and cardiac myocytes from Ckmm-Cre+/- ;Ercc1-/fl mice were hypersensitive to genotoxins, resulting in apoptosis. p53 levels and target gene expression, including several antioxidants, were increased in cardiac tissue from Ckmm-Cre+/- ;Ercc1-/fl and Ercc1-/D mice. Despite this, cardiac tissue from older mutant mice showed evidence of increased oxidative stress. Genetic or pharmacologic inhibition of p53 attenuated apoptosis and improved disease markers. Similarly, overexpression of mitochondrial-targeted catalase improved disease markers. Together, these data support the conclusion that DNA damage produced endogenously can drive cardiac disease and does so mechanistically via chronic activation of p53 and increased oxidative stress, driving cardiac myocyte apoptosis, dilated cardiomyopathy, and sudden death.