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Updated: Jul 4, 2025
A Doxorubicin-Induced Murine Model of Dilated Cardiomyopathy In Vivo
Published on: May 16, 2020
USP36-mediated PARP1 deubiquitination in doxorubicin-induced cardiomyopathy
Dongchen Wang1, Zihao Jiang1, Junyan Kan1
1Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.
Abstract:
Doxorubicin (Dox) is a potent antineoplastic agent, but its use is curtailed by severe cardiotoxicity, known as Dox-induced cardiomyopathy (DIC). The molecular mechanism underlying this cardiotoxicity remains unclear. Our current study investigates the role of Ubiquitin-Specific Protease 36 (USP36), a nucleolar deubiquitinating enzyme (DUB), in the progression of DIC and its mechanism. We found increased USP36 expression in neonatal rat cardiomyocytes and H9C2 cells exposed to Dox. Silencing USP36 significantly mitigated Dox-induced oxidative stress injury and apoptosis in vitro. Mechanistically, USP36 upregulation positively correlated with Poly (ADP-ribose) polymerase 1 (PARP1) expression, and its knockdown led to a reduction in PARP1 levels. Further investigation revealed that USP36 could bind to and mediate the deubiquitination of PARP1, thereby increasing its protein stability in cardiomyocytes upon Dox exposure. Moreover, overexpression of wild-type (WT) USP36 plasmid, but not its catalytically inactive mutant (C131A), stabilized PARP1 in HEK293T cells. We also established a DIC model in mice and observed significant upregulation of USP36 in the heart. Cardiac knockdown of USP36 in mice using a type 9 recombinant adeno-associated virus (rAAV9)-shUSP36 significantly preserved cardiac function after Dox treatment and protected against Dox-induced structural changes within the myocardium. In conclusion, these findings suggest that Dox promotes DIC progression by activating USP36-mediated PARP1 deubiquitination. This novel USP36/PARP1 axis may play a significant regulatory role in the pathogenesis of DIC.
Insights
Doxorubicin (Dox) chemotherapy causes heart damage (cardiomyopathy). This study reveals that Dox activates USP36, which stabilizes PARP1, leading to heart toxicity. Inhibiting USP36 protects the heart from Dox damage.
Area of Science:
- Biochemistry
- Molecular Biology
- Cardiology
Background:
- Doxorubicin (Dox) is a vital chemotherapy drug, but its clinical use is limited by severe cardiotoxicity, termed Dox-induced cardiomyopathy (DIC).
- The precise molecular mechanisms driving DIC remain incompletely understood, hindering the development of targeted protective strategies.
- Ubiquitin-Specific Protease 36 (USP36), a nucleolar deubiquitinating enzyme, has emerged as a potential factor in cellular stress responses.
Purpose of the Study:
- To investigate the role and mechanism of Ubiquitin-Specific Protease 36 (USP36) in the pathogenesis of Dox-induced cardiomyopathy (DIC).
- To determine if USP36 modulates the expression or stability of key proteins involved in Dox-induced cellular damage.
- To evaluate the therapeutic potential of targeting USP36 to mitigate Dox-induced cardiotoxicity in preclinical models.
Main Methods:
- Assessed USP36 expression in cardiomyocytes and H9C2 cells treated with Dox.
- Utilized USP36 knockdown and overexpression models in vitro (cell cultures) and in vivo (mice) to study its effects.
- Investigated the interaction and deubiquitination activity of USP36 on Poly (ADP-ribose) polymerase 1 (PARP1) using co-immunoprecipitation and Western blotting.
- Evaluated cardiac function and structure in a mouse model of DIC with cardiac-specific USP36 knockdown via rAAV9 delivery.
Main Results:
- USP36 expression was significantly upregulated in cardiomyocytes and H9C2 cells upon Dox exposure.
- Silencing USP36 expression attenuated Dox-induced oxidative stress, apoptosis, and preserved cardiac function in vivo.
- USP36 directly deubiquitinates and stabilizes PARP1, promoting its accumulation in cardiomyocytes following Dox treatment.
- Cardiac-specific knockdown of USP36 in mice significantly protected against Dox-induced cardiotoxicity and preserved heart function.
Conclusions:
- Doxorubicin administration activates USP36, which subsequently deubiquitinates and stabilizes PARP1, contributing to the development of Dox-induced cardiomyopathy.
- The novel USP36/PARP1 signaling axis represents a critical pathway in the pathogenesis of DIC.
- Targeting USP36 may offer a promising therapeutic strategy to prevent or treat Dox-induced cardiotoxicity.
