Isoflurane alleviates hypoxia/reoxygenation induced myocardial injury by reducing miR-744 mediated SIRT6

Abstract

Background

The objective of this study was to investigate the role of miR-744 and its target genes in ISO protection against hypoxia/reoxygenation (H/R) induced myocardial injury.

Methods

Rat cardiomyocytes H9c2 was used to establish an H/R model in vitro, and the level of miR-744 mRNA was detected by fluorescence quantitative PCR. CCK-8 and flow cytometry was used to detected cell viability and apoptosis. Myocardial injury markers CK-MB, cTnI, and LDH were detected by enzyme-linked immunosorbent assay (ELISA). Online bioinformatics software miRDB and miRWalk predicts miR-744 target and its potential binding site, and verifies the target by luciferase reporter assay.

Results

After H/R induction, miR-744 mRNA level was remarkedly increased, cell viability was deceased, and apoptosis was increased (p < 0.05). Myocardial injury markers CK-MB, cTnI, and LDH expressions were also increased (p < 0.05). However, ISO pretreatment can significantly alleviate the decrease in cell viability induced by H/R, the increase of cell apoptosis, and the increase of myocardial injury markers, and it play a cardioprotective effect (p < 0.05). More importantly, elevated miR-744 remarkedly weakened the protective effect of ISO on H/R-induced myocardial injury, resulting in decreased cell viability, increased apoptosis, and elevated concentration of myocardial injury indicators (p < 0.05). Luciferase reporter assay confirmed that Sirtuins6 (SIRT6) is a potential target of miR-744 and decreased in H/R-induced myocardial injury, and ISO exposure can reverse its level (p < 0.05).

Conclusion

Our findings provide new insights that ISO pretreatment can remarkedly regulate miR-744 and its downstream target SIRT6 to mitigate myocardial injury induced by H/R.

Keywords:

• miR-744
• isoflurane; myocardial injury
• hypoxia/reoxygenation

Acknowledgement

The authors thanks to Weihua Fan and Lingyu Lu for their constructive comments and contributions to the revision of the manuscript.

Disclosure statement

There is no conflict of interest in this study.

Data availability statement

Data may be provided by the corresponding author.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [NO. 81801193].