Int J Biol Sci 2019; 15(10):2051-2064. doi:10.7150/ijbs.36532

Research Paper

Circular RNA CircEZH2 Suppresses Transmissible Gastroenteritis Coronavirus-induced Opening of Mitochondrial Permeability Transition Pore via Targeting MiR-22 in IPEC-J2

Xiaomin Zhao*, Xuelian Ma*, Jianxiong Guo, Mi Mi, Kaili Wang, Chuyi Zhang, Xiaoyi Tang, Lingling Chang, Yong Huang, Dewen Tong

College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China
* These authors contributed equally to this work.

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Citation:
Zhao X, Ma X, Guo J, Mi M, Wang K, Zhang C, Tang X, Chang L, Huang Y, Tong D. Circular RNA CircEZH2 Suppresses Transmissible Gastroenteritis Coronavirus-induced Opening of Mitochondrial Permeability Transition Pore via Targeting MiR-22 in IPEC-J2. Int J Biol Sci 2019; 15(10):2051-2064. doi:10.7150/ijbs.36532. Available from http://www.ijbs.com/v15p2051.htm

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Abstract

Transmissible gastroenteritis (TGE) is a contagious and infectious disease that is characterized by severe vomiting and diarrhea of swine , especially piglet, and caused by transmissible gastroenteritis coronavirus (TGEV) . TGEV infection provokes mitochondrial damage of porcine intestinal epthelial cell (IPEC), which is responsible for inflammation and cell death. In our previous study, we have demonstrated that circular RNA circEZH2 was down-regulated during TGEV infection and promoted the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) via targeting miR-22 in porcine intestinal epithelial cell line (IPEC-J2). Activation of NF-κB is an important factor for mitochondrial damage. Mitochondrial permeability transition pore (mPTP) opening is a key reason for mitochondrial damage. So, we speculate that circEZH2 may regulate TGEV-induced mPTP opening via NF-kB pathway. In the present study, we found that mPTP opening of IPEC-J2 was occured during TGEV infection and suppressed by circEZH2 via attaching miR-22. Hexokinase 2 (HK2) and interleukin 6 (IL-6) were identified as the targets of miR-22. Silencing HK2 enhanced TGEV-induced mPTP opening, while no effect on NF-κB pathway. Silencing IL-6 promoted TGEV-induced mPTP opening and inhibited NF-κB pathway. Inhibitor of NF-κB increased TGEV-induced mPTP opening. The data revealed that TGEV-induced mPTP opening was regulated via two pathways: circEZH2/miR-22/HK2 axis and circEZH2/miR-22/IL-6/NF-κB axis.

Keywords: transmissible gastroenteritis coronavirus virus, circular RNA, microRNA, mitochondrial permeability transition pore, NF-κB