Related Experiment Video
Updated: Nov 28, 2025
A Doxorubicin-Induced Murine Model of Dilated Cardiomyopathy In Vivo
Published on: May 16, 2020
Circular RNA Arhgap12 modulates doxorubicin-induced cardiotoxicity by sponging miR-135a-5p
Xuejun Wang1, Zijie Cheng1, Jia Xu1
1Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Aim:
This study aimed to investigate the regulatory role of differentially-expressed circular RNAs (circRNAs) in mouse cardiomyocytes during doxorubicin (DOX)-induced cardiotoxicity.
Main Methods:
Two groups of mice were injected with equal volumes (0.1 mL) of normal saline and DOX. Mouse heart tissue was isolated and digested for total RNA extraction and then subjected to next-generation RNA-sequencing. Expression profiles of circRNAs and circRNA-miRNA-mRNA networks were also constructed. Overall, 48 upregulated and 16 downregulated circRNAs were found to be statistically significant (p < 0.05) in the DOX-injected group. Bioinformatics analysis revealed several potential biological pathways that might be related to apoptosis caused by DOX-induced cardiotoxicity. In addition, using qRT-PCR, we found that a circRNA coded by the Arhgap12 gene, termed circArhgap12, was upregulated in the mouse heart tissue upon DOX intervention. CircArhgap12 enhanced apoptotic cell rate, as assessed using terminal-deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay, and increased reactive oxygen species and malondialdehyde release as well as superoxide dismutase and caspase-3 activation. Using a luciferase reporter assay, we found that circArhgap12 could sponge miR-135a-5p. In rat primary cardiomyocytes, we found that si-circArhgap12 promoted apoptosis and oxidative stress by sponging the miR-135a-5p inhibitor. Using bioinformatics analysis and luciferase reporter assay, we found that miR-135a-5p might have a potential target site for ADCY1 mRNA.
Key Findings:
Our research demonstrated that the expression profile of circRNAs was modified significantly and that circArhgap12 might play a competitive role among endogenous RNAs in mouse cardiomyocytes during DOX-induced cardiotoxicity.
Significance:
Our study may provide a preliminary understanding of DOX-induced cardiotoxicity modulated by circRNA and its competing endogenous RNAs network.
Insights
Circular RNAs (circRNAs) are altered in doxorubicin-induced cardiotoxicity. CircArhgap12 exacerbates heart cell damage by interacting with miR-135a-5p, offering insights into this condition.
Area of Science:
- Cardiovascular Biology
- Molecular Biology
- Genomics
Background:
- Doxorubicin (DOX) is a widely used chemotherapy agent with known cardiotoxic side effects.
- Circular RNAs (circRNAs) are emerging as critical regulators in various biological processes, including cardiac function.
- Understanding the molecular mechanisms underlying DOX-induced cardiotoxicity is crucial for developing protective strategies.
Purpose of the Study:
- To investigate the regulatory role of differentially-expressed circRNAs in mouse cardiomyocytes during DOX-induced cardiotoxicity.
- To identify specific circRNAs and their associated pathways involved in DOX-induced cardiac damage.
- To elucidate the molecular interactions between circRNAs, microRNAs (miRNAs), and messenger RNAs (mRNAs) in the context of cardiotoxicity.
Main Methods:
- Differential expression analysis of circRNAs in mouse heart tissue using next-generation RNA sequencing after DOX injection.
- Construction of circRNA-miRNA-mRNA regulatory networks.
- Validation of circArhgap12 expression using quantitative real-time PCR (qRT-PCR).
- Assessment of apoptosis, reactive oxygen species (ROS), and oxidative stress markers (malondialdehyde, superoxide dismutase, caspase-3) in cardiomyocytes.
- Luciferase reporter assays to confirm circRNA-miRNA interactions and miRNA-mRNA targeting.
Main Results:
- Significant alterations in circRNA expression profiles were observed in DOX-treated mouse hearts, with 48 upregulated and 16 downregulated circRNAs identified.
- CircArhgap12 was significantly upregulated in DOX-treated hearts and was found to enhance cardiomyocyte apoptosis and oxidative stress.
- CircArhgap12 was demonstrated to sponge miR-135a-5p, and miR-135a-5p was predicted to target ADCY1 mRNA.
Conclusions:
- CircRNAs, particularly circArhgap12, play a significant role in the pathogenesis of DOX-induced cardiotoxicity.
- The circRNA-miRNA-mRNA network, involving circArhgap12 and miR-135a-5p, is a key modulator of DOX-induced cardiomyocyte apoptosis and oxidative stress.
- These findings provide a preliminary understanding of circRNA-mediated regulation in DOX cardiotoxicity, suggesting potential therapeutic targets.
Related Concept Videos
02:15Experimental RNAi
01:23RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
01:22MicroRNAs