Cyclophilin A mediates coelomocyte apoptosis via the NF-κB/Bcl-2 signaling pathway in Apostichopus japonicus. (June 2020)

• Record Type: Journal Article
• Authors: Liu, Jiqing; Zhao, Xuelin; Lv, Zhimeng; Guo, Ming; Li, Chenghua
• Is Part Of: Developmental and comparative immunology. Volume 107(2020)
• Publication Date: 2020-06
• Subjects: Apostichopus japonicas -- Cyclophilin A -- B-cell lymphoma-2 -- Promotor; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2020.103657
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: As a multifunctional protein, cyclophilin A (CypA) plays an important role in cell apoptosis. In our previous work, we found that CypA from Apostichopus japonicus (AjCypA), as a cofactor, could modulate nuclear translocation of NF-κB. However, the immune function of AjCypA is largely unknown. In the present study, we found that siRNA-mediated AjCypA knockdown in vivo significantly increased the coelomocyte apoptosis rate. In addition, the expression of B-cell lymphoma-2 (AjBcl-2, an anti-apoptosis gene) was synchronously downregulated. To better understand the connection between AjCypA and AjBcl-2 expression, we cloned the promoter of AjBcl-2 via genomic walking, which spanned 1870 bp and contained four potential binding sites of NF-κB. Dual-luciferase reporter assay revealed that the full-length sequence and all truncated fragments exhibited high transcriptional activity. Moreover, 1 μg/mL LPS exposure significantly increased the luciferase activity of P1 (−1870/+57) by 2.31-fold and 3.15-fold at 12 and 24 h, respectively. Furthermore, the four potential NF-κB binding sites and pCMV-Flag2C-AjNF-κB co-transfection assay demonstrated that NF-κB could regulate the expression of AjBcl-2 via the NF-κB binding sites of AjBcl-2 promoter. All results supported that AjCypA mediates coelomocyte apoptosis via NF-κB/AjBcl-2 signaling pathway in A. japonicus. Highlights: AjCypA knockdown could promote the apoptosis levels and depress AjBcl-2 expression. NF-κB could regulate AjBcl-2 gene expression via binding to AjBcl-2 promoter. AjCypA mediates coelomocyte apoptosis via the NF-κB/AjBcl-2 signaling pathway.