PRRSV alters mA methylation and alternative splicing to regulate immune, extracellular matrix-associated function.

The alternative splicing and N6-methyladenosine (mA) modifications occurring during porcine reproductive and respiratory syndrome virus (PRRSV) infections remain poorly understood. Transcriptome and MeRIP-seq analyses were performed to identify the gene expression changes, splicing and m6A modifications in the lungs of PRRSV-infected pigs. In total, 1624 differentially expressed genes (DEGs) were observed between PRRSV-infected and uninfected pigs. We observed significant alterations in alternative splicing (54,367 events) and m6A modifications (2265 DASEs) in numerous genes, including LMO7, SLC25A27, ZNF185, and ECM1, during PRRSV infection. LMO7 and ZNF185 exhibited alternative splicing variants and reduced mRNA expression levels following PRRSV infection. Notably, LMO7 inhibited c-JUN, SMAD3, and FAK expression, whereas ZNF185 affected the expression of FAK, CDH1, and GSK3β downstream. Additionally, ECM1 influenced FAK expression by targeting ITGB3 and AKT2, suggesting its involvement in extracellular matrix accumulation through the ITGB3-AKT2/FAK pathway. These changes may facilitate viral invasion and replication by modulating the expression of genes and proteins participating in crucial cellular processes associated with immunity and the extracellular matrix. We highlight the importance of these genes and their associated pathways in PRRSV infections and suggest that targeting these may be a promising therapeutic approach for treating viral infections.