Background/aim
Congenital heart disease (CHD) is a catastrophic disease. Emodin possesses biological properties in protecting against some diseases. Our study investigated to explore the effects of emodin on hypoxia‐stimulated cardiomyocytes, which mimicked CHD in vitro.
Methods
H9c2 cells were stimulated with hypoxia and then the cells were treated with or without emodin, and/or transfected with miR‐26a mimic, pcDNA‐survivin and their corresponding negative control (NC). Cell viability and cell apoptosis were detected by Cell Counting kit‐8 assay and flow cytometry, respectively. In addition, the expression of apoptotic proteins, Janus kinase 1 (JNK)/signal transducer and activator of transcription 3 (STAT3) pathway factors, and survivin were evaluated by using Western blot analysis. The expression of miR‐26a was analyzed by quantitative real time polymerase chain reaction (qRT‐PCR). Moreover, the target of miR‐26a was verified by using a luciferase report assay.
Results
Hypoxia significantly decreased cell viability and increased cell apoptosis, and the accumulated levels of cleaved caspase‐3 and cleaved‐caspase‐9 were upregulated by hypoxia compared with the control. However, emodin administration led to the opposite result. A further result showed that emodin increased the phosphorylation of JNK/STAT3 pathway–related proteins and the pathway inhibitor AG490 impaired the protective effects of emodin on hypoxia‐induced injury. In addition, emodin negatively regulated the miR‐26a expression, and overexpression of miR‐26a enhanced cell apoptosis and upregulated the expression of cleaved‐caspase‐3 and cleaved‐caspase‐9 compared with the NC. Moreover, emodin statistically upregulated the expression of survivin, and overexpression of miR‐26a decreased the expression of survivin. The luciferase of miR‐26a overexpression was decreased in the wild type of the survivin group.
Conclusion
Emodin protects hypoxia‐induced cell injury as evidenced by increasing cell viability and decreasing apoptosis through downregulation of miR‐26a as well as activation of the JNK/STAT3 pathway.