Newcastle disease virus activates methylation-related enzymes to reprogram m⁶A methylation in infected cells

Newcastle disease virus (NDV) is a paramyxovirus with high incidence and transmissibility in birds and is currently being developed for cancer therapy. N⁶-methyladenosine (m⁶A) is a common epigenetic modification of RNA. In this study, we aimed to determine whether this modification plays an important role in NDV infection. We found that methylation-related enzymes were activated in NDV-infected cells, and the abundance of m⁶A notably increased in vivo and in vitro. Further functional experiments showed that m⁶A methylation negatively regulates NDV infection. Methylated RNA immunoprecipitation sequencing revealed that the m⁶A-methylated peaks on different functional components of host genes shifted, underwent reprogramming, and were primarily enriched in the coding sequence after NDV infection. The differentially modified genes were mainly enriched in cellular components, as well as autophagy and ubiquitination-mediated proteolysis signaling pathways. Association analysis of RNA sequencing results showed changes in m⁶A regulated mRNA transcription and revealed that YTHDC1 is a methylation-related enzyme with important catalytic and recognition roles during NDV infection. Additionally, m⁶A-methylated peaks were detected in the NDV genome, which may be regulated by methylation-related enzymes in the host, subsequently affecting viral replication. Comprehensive analysis of the m⁶A expression profile after NDV infection indicated that NDV may cause reprogramming of m⁶A methylation and that m⁶A plays important roles during infection. Overall, these findings provide insights into the epigenetic etiology and pathogenesis of NDV.