The involvement of CgCaspase-3 in regulating the expressions of proinflammatory cytokines through NF-κB/Rel signaling pathway in oysters

Cysteinyl aspartate specific proteinase-3 (Caspase-3) is a prominent mediator of apoptosis and participates in the cell death signaling cascade. In our previous study, Cg Caspase-3 identified from Crassostrea gigas was involved in Cg GSDME-dependent pyroptosis. In the present study, Cg Caspase-3 was demonstrated to regulate the expressions of proinflammatory cytokines through nuclear factor kappa B (NF-κB) signaling pathway. In haemocytes of Ac-DEVD-CHO-treated and Cg Caspase-3-RNAi oysters, the nuclear translocation of NF-κB/Rel was inhibited at 24 h after Vibrio splendidus stimulation. The mRNA expressions of interleukins 17s ( Cg IL17–2, Cg IL17–3, and Cg IL17–6), tumor necrosis factor-1 ( Cg TNF-1), high mobility group box-1 protein ( Cg HMGB1) and interferon-like protein ( Cg IFNLP) were significantly decreased in haemocytes of Cg Caspase-3-RNAi or Cg Rel-RNAi oysters, respectively. In addition, the phenomenon of gill swelling and cilia shedding was reduced in Cg Caspase-3-RNAi oysters after V. splendidus stimulation. These results indicated that Cg Caspase-3 was involved in regulating bacteria-induced inflammation through NF-κB/Rel signaling pathway.