NSUN2 inhibits NCOA4 expression to alleviate ferroptosis and inflammation in sepsis-induced myocardial injury in a mC manner.

BACKGROUND

Sepsis-induced myocardial injury (SIMI) leads to high morbidity and mortality. The 5-methylcytosine (mC) RNA methyltransferase NOL1/NOP2/SUN domain (NSUN)2 is a therapeutic target for many diseases. The purpose of this study was to investigate the role of NSUN2 in SIMI and the potential mechanism.

METHODS

Both an in vivo cecum ligation and puncture (CLP) SIMI rat model and an in vitro lipopolysaccharide (LPS)-treated H9c2 cardiomyocytes model were established. Reverse transcription (RT)-quantitative polymerase chain reaction (qPCR) was used to detect mC-related and ferroptosis-related mRNA levels. Enzyme-linked immunosorbent assay was performed to assess inflammatory cytokines levels. Ferroptosis-related indicators were detected by commercial kits and Western blot. Methylated RNA immunoprecipitation (MeRIP)-qPCR assay was performed to detect the mC level of ferroptosis-related mRNAs. RIP assay was used to explore the interaction between NSUN2 and nuclear receptor coactivator (NCOA)4. The mC site of NCOA4 was analyzed by dual-luciferase reporter assay.

RESULTS

NSUN2 alleviated LPS-induced SIMI by increasing cell viability and inhibiting inflammation and ferroptosis. In addition, NSUN2 inhibited NCOA4 expression in a mC-dependent manner. Moreover, overexpressing NCOA4 downregulated cell viability and upregulated LDH activity, inflammation, and ferroptosis in LPS-induced SIMI. In in vivo studies, NSUN2 overexpression reversed CLP-induced myocardial injury, cardiac dysfunction, inflammation, and ferroptosis.

CONCLUSIONS

NSUN2 inhibited NCOA4 expression to alleviate ferroptosis and inflammation in SIMI in a mC manner, which might provide new information for the clinical treatment of SIMI.