Circular RNA hsa_circ_0000848 Regulates Cardiomyocyte Proliferation and Apoptosis Under Hypoxia via Recruiting ELAVL1 and Stabilizing SMAD7 mRNA

Background: Myocardial infarction has been recognized globally as a serious problem featured with high mortality and morbidity. In addition, hypoxia represents the central feature of myocardial infarction. Recently, it has been reported that circular RNAs can exert critical functions in the biological processes of diseases. However, the functions of most circular RNAs remain unclear in cells cultured under hypoxic conditions. In this study, we focused on exploring the role of circ_SMAD7 (namely hsa_circ_0000848 in this study) in cardiomyocyte cells cultured under hypoxic conditions to provide a novel insight for future myocardial infarction studies.
Methods: Firstly, a real-time quantitative polymerase chain reaction assay was adopted to analyze hsa_circ_0000848 expression. Functional assays were performed to detect the functions of hsa_circ_0000848 in cardiomyocyte cells cultured under hypoxic conditions. Furthermore, mechanism assays were implemented to explore the regulatory mechanism of hsa_circ_0000848.
Results: Hsa_circ_0000848 was notably downregulated in hypoxia-induced cardiomyocytes. The silencing of hsa_circ_0000848 hindered the proliferation while accelerating the apoptosis of hypoxia-induced cardiomyocytes cells. Moreover, hsa_circ_0000848 interacted with ELAV-like RNA-binding protein 1 protein to stabilize SMAD family member 7 mRNA. Moreover, SMAD family member 7 overexpression could reverse the suppressive effect of hsa_circ_0000848 knockdown on myocardial infarction progression.
Conclusions: Our research was the first in the field to confirm that the hsa_circ_0000848/ ELAV-like RNA-binding protein 1/SMAD family member 7 axis could affect the development of cardiomyocyte cells cultured under hypoxia, indicating that hsa_circ_0000848 might function as a novel biomarker in cells under hypoxia thus laying the groundwork for future study on myocardial infarction.