Identification and functional analysis of <i>circRIPK2</i> in lipopolysaccharide induced chicken macrophages

1. It was hypothesised that a circular RIPK2 (circRIPK2) highly expressed in chicken macrophages plays an important role during bacterial infection. 2. After PCR amplification, Sanger sequencing and RNase R exonuclease treatment of chicken macrophages, it was found that circRIPK2 was a stable circular RNA, which was formed by reverse splicing of exons 4 to 9 of the RIPK2. 3. The circRIPK2 can promote the lipopolysaccharide (LPS) induced cellular injury by reducing cell viability and increasing the expression of pro-inflammatory cytokines and apoptosis genes. 4. Six miRNAs were identified as interacting with circRIPK2, potentially targeting 1,817 genes, which were significantly enriched in the Wnt signalling pathway, adherens junction and NOD-like receptor signalling pathway. 5. This study provides better understanding of the function of circRIPK2, which may prove a potential biomarker and indicate potential targets for the treatment of bacterial infection.