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Updated: Mar 5, 2026
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
MiR-146b protects cardiomyocytes injury in myocardial ischemia/reperfusion by targeting Smad4
Yun-Feng Di1, De-Cai Li1, Yan-Qing Shen2
1Department of Cardiology, Sichuan Mianyang 404 Hospital (The Second Affiliated Hospital of North Sichuan Medical College) No.56, Fucheng District, Mianyang City 621000, Sichuan Province, China.
Abstract:
MicroRNAs, a class of small and non-encoding RNAs that transcriptionally or post-transcriptionally modulate the expression of their target genes, have been implicated as critical regulatory molecules in many cardiovascular diseases, including ischemia-/reperfusion-induced cardiac injury. In the present study, we report on the role of miR-146b in myocardial I/R injury and the underlying cardio-protective mechanism. Antagomir-146b was used to explore the effects of miR-146b on cardiac ischemia/reperfusion injury (30 min ischemia followed by 180 min reperfusion). As predicted, miR-146b overexpression significantly reduced the infarct size and cardiomyocytes apoptosis and release of creatine kinase and lactate dehydrogenase. In addition, miR-146b attenuated H9c2 cell apoptosis. Furthermore, Smad4 was predicted and verified as a potential miR-146b target using bioinformatics and luciferase assay. In summary, this study demonstrated that miR-146b plays a critical protective role in cardiac ischemic injury and may provide a new therapeutic approach for the treatment of myocardial I/R injury.
Insights
MicroRNA-146b (miR-146b) protects the heart from injury caused by ischemia and reperfusion. This study shows miR-146b reduces heart cell death and may offer new therapeutic strategies for cardiac injury.
Area of Science:
- Molecular Biology
- Cardiovascular Research
- Biochemistry
Background:
- MicroRNAs (miRNAs) are small non-coding RNAs regulating gene expression.
- miRNAs are implicated in cardiovascular diseases, including ischemia/reperfusion (I/R) injury.
- The specific role of miR-146b in myocardial I/R injury requires elucidation.
Purpose of the Study:
- To investigate the role of miR-146b in myocardial ischemia/reperfusion (I/R) injury.
- To explore the cardioprotective mechanism mediated by miR-146b.
Main Methods:
- Utilized antagomir-146b to study the effects of miR-146b inhibition on cardiac I/R injury.
- Assessed infarct size, cardiomyocyte apoptosis, and cardiac enzyme release (creatine kinase, lactate dehydrogenase).
- Investigated miR-146b's effect on H9c2 cell apoptosis.
- Employed bioinformatics and luciferase assays to identify and verify Smad4 as a miR-146b target.
Main Results:
- Overexpression of miR-146b significantly reduced infarct size in myocardial I/R injury.
- miR-146b attenuated cardiomyocyte apoptosis and decreased the release of creatine kinase and lactate dehydrogenase.
- miR-146b also reduced apoptosis in H9c2 cells, and Smad4 was confirmed as a direct target.
Conclusions:
- miR-146b plays a critical protective role in mitigating cardiac ischemic injury.
- The findings suggest miR-146b exerts its protective effects, at least partly, through targeting Smad4.
- miR-146b represents a potential novel therapeutic target for treating myocardial I/R injury.
