Circular RNA expression profile of spleen in a Clostridium perfringens type C-induced piglet model of necrotizing enteritis.

Clostridium perfringens type C is a pathogen that causes necrotizing enteritis (NE), which is an intestinal tract disease in piglets. The pathogenesis of C. perfringens type C-induced NE is still unclear, leading to a lack of effective therapies. Earlier studies have reported that circular RNAs (circRNAs) are involved in the pathogenic processes of various diseases. However, it is not known if circRNAs in spleen play a role in C. perfringens type C infection in NE. To address this question, we infected 7-day-old piglets with C. perfringens type C to induce NE. Hematoxylin and eosin staining of small intestine revealed inflammation, atrophy and shedding of intestinal villi, and intestinal mucosal necrosis. We observed increased expression of cytokine genes (such as IL-1β and IL-6) and inflammation in the spleen. In addition, we used RNA-seq and bioinformatics analysis to examine changes in circRNA expression. A total of 103 circRNAs were found to be differentially expressed in NE, and Gene Ontology analysis revealed that the genes producing differentially expressed circRNAs were enriched in regulation of the cellular metabolic process protein binding. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the genes producing differentially expressed circRNAs were involved in the tumor necrosis factor signaling pathway, T cell receptor signaling pathway and nuclear factor-κB signaling pathway. Finally, we found eight circRNAs (including circ_0002220 and circ_0000821) that are related to NE. Therefore, our study provides new insights into the mechanisms underlying C. perfringens type C infection in piglets.