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Updated: May 17, 2026
In vitro Assessment of Myocardial Protection following Hypothermia-Preconditioning in a Human Cardiac Myocytes Model
Published on: October 27, 2020
Induction of microRNA-24 by HIF-1 protects against ischemic injury in rat cardiomyocytes
1Department of Physiology, Second Military Medical University, Shanghai, PR China.
Abstract:
MicroRNAs are emerging as important regulators of cardiac function. This study investigated the role of microRNA-24 (miR-24) in ischemic cardiomyocytes, based on the observation that miR-24 expression was significantly enhanced in the ischemic myocardium of rats. Using primary cultured rat cardiomyocytes, cell injury was induced by ischemic conditions, and the cells were evaluated for changes in lactate dehydrogenase (LDH) release, cell viability, apoptosis and necrosis. The results showed that miR-24 was increased in myocytes exposed to ischemia. When miR-24 was further overexpressed in ischemic myocytes using the mimic RNA sequence, LDH release was reduced, cell viability was enhanced, and apoptosis and necrosis rates were both decreased. By contrast, a deficiency in miR-24 resulted in the largest LDH release, lowest cell viability and highest apoptosis and necrosis rates in normal and ischemic myocytes, with significant changes compared to that of non-transfected myocytes. Additionally, the mRNA and protein levels of the pro-apoptotic gene, BCL2L11, were down-regulated by miR-24 overexpression and up-regulated by miR-24 deficiency. The luciferase reporter assay confirmed BCL2L11 to be a target of miR-24. Overall, this study showed a protective role for miR-24 against myocardial ischemia by inhibiting BCL2L11, and may represent a potential novel treatment for ischemic heart disease.
Insights
MicroRNA-24 (miR-24) protects heart cells from ischemic injury by reducing cell death and improving viability. This finding suggests miR-24 as a potential therapeutic target for ischemic heart disease.
Area of Science:
- Cardiovascular Biology
- Molecular Cardiology
- MicroRNA Therapeutics
Background:
- MicroRNAs are key regulators of cardiac function.
- MicroRNA-24 (miR-24) expression is elevated in ischemic heart tissue.
- Understanding miR-24's role in ischemic cardiomyocytes is crucial.
Purpose of the Study:
- To investigate the function of miR-24 in cardiomyocytes under ischemic conditions.
- To determine if miR-24 influences cell survival and apoptosis during ischemia.
- To identify the molecular targets of miR-24 in the context of myocardial ischemia.
Main Methods:
- Primary rat cardiomyocyte cultures subjected to induced ischemia.
- Assessment of cell injury markers: lactate dehydrogenase (LDH) release, cell viability, apoptosis, and necrosis.
- Manipulation of miR-24 levels using mimic RNA and deficiency models.
- Quantitative analysis of BCL2L11 gene and protein expression.
- Luciferase reporter assay to confirm gene targets.
Main Results:
- miR-24 levels increased in cardiomyocytes exposed to ischemia.
- Overexpression of miR-24 reduced LDH release, enhanced cell viability, and decreased apoptosis and necrosis.
- miR-24 deficiency exacerbated cell injury, increasing LDH release and apoptosis/necrosis.
- miR-24 directly targeted and down-regulated the pro-apoptotic gene BCL2L11.
Conclusions:
- miR-24 exerts a protective effect against myocardial ischemia.
- This protection is mediated through the inhibition of the pro-apoptotic factor BCL2L11.
- miR-24 represents a promising therapeutic candidate for treating ischemic heart disease.
