N 6-methyladenosine modification contributes to respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the second leading cause of death due to lower respiratory tract infections. Effective prevention and treatment measures are lacking, posing a huge socioeconomic burden to the world. N 6-methyladenosine (m6A) is the most common internal modification in messenger RNA and noncoding RNA. Numerous recent studies have shown that the dysregulation of m6A modification is associated with diseases caused by pathogenic viruses.

We uncovered a significant role for m6A modification during RSV infection. Also, a correlation was found between m6A and autophagy, providing new ideas for therapeutic advancements in RSV treatment.

The changes in m6A modification were evaluated using m6A RNA methylation assay. The differences in gene expression levels of various m6A-modifying enzymes were observed using Quantitative Real-time PCR (qRT-PCR) during RSV infection. The autophagosomes were observed using transmission electron microscopy, and the expression of autophagy-associated protein Microtubule Associated Protein 1 Light Chain 3 Beta Ⅱ/Ⅰ (LC3B Ⅱ/Ⅰ) and Beclin1 in Human Normal Lung Epithelial Cells (BEAS-2B) cells using Western blot during RSV infection. The significantly differentially expressed genes were screened guided by bioinformatics. Their relationship with m6A-modifying enzymes was analyzed through protein-protein interaction network and expression correlation analysis.

The m6A abundance decreased and demethylase Fat Mass and Obesity- Associated Protein (FTO) significantly increased during RSV infection after 24 h. We also found that the DNA Damage-Inducible Transcript 3 Protein (DDIT3) level significantly increased during RSV infection after 24 h and observed autophagosomes in BEAS-2B cells. In addition, RSV infection could cause the upregulation of LC3B Ⅱ/Ⅰ and Beclin1. The expression correlation analysis showed that DDIT3 levels were positively correlated with the FTO level, and Methyltransferase Like 3 (METTL3), RNA Binding Motif Protein 15B (RBM15B), YTH Domain-Containing Family Protein 1 (YTHDF1), and levels were negatively correlated with the DDIT3 level. Conclusions: We uncovered a significant role for m6A modification during RSV infection. Also, a correlation was found between m6A and autophagy, providing new ideas for therapeutic advancements in RSV treatment.