Glaesserella parasuis Infection Modulates the Transcriptome of Porcine Peritoneal Mesothelial Primary Cells: Implications for Understanding Peritoneal Invasion Mechanisms

, GPS) infection in pigs, typically presenting as peritonitis, pleuritis, pericarditis, meningitis, and arthritis, resulting in heavy economic losses in the swine industry. However, the current research on the pathogenesis of infectious peritonitis, particularly that caused by GPS, remains limited, and this condition has long been poorly reported in both clinical practice and research. In this study, we investigated the overall changes in gene expression in porcine peritoneal mesothelial primary cells (PPMCs) following a GPS infection using transcriptomics analysis. A total of 779 differentially expressed genes (DEGs) were identified after 12 h of infecting the PPMCs with GPS, resulting in 253 and 526 genes being upregulated and downregulated, respectively. Additionally, 220 DEGs, mainly involved in the NOD-like receptor signaling pathway, the TNF signaling pathway, and the metabolic pathway, were enriched in the KEGG analysis. These pathways were associated with the main DEGs (IL-1β, IL6, CCL5, CCL2 and NFKBIA), and their gene expression levels were verified through quantitative real-time fluorescence PCR (qRT-PCR). Moreover, oxidative phosphorylation, Salmonella infection, rheumatoid arthritis, and other regulating pathways were clustered together. Our results provide insights into the molecular mechanism underlying GPS-induced peritonitis in swine, identify novel therapeutic targets, and provide research direction for the control and prevention of GPS infections. These insights provide a foundational basis for advancing intervention and prevention approaches for this overlooked yet clinically significant manifestation of polyserositis.