title: miR-27b attenuates apoptosis induced by transmissible gastroenteritis virus (TGEV) infection via targeting runt-related transcription factor 1 (RUNX1).
abstract: Transmissible gastroenteritis virus (TGEV), belonging to the coronaviridae family, is the key cause of the fatal diarrhea of piglets and results in many pathological processes. microRNAs (miRNAs) play a key role in the regulation of virus-induced apoptosis. During the process of apoptosis induced by TGEV infection in PK-15 cells, the miR-27b is notably down-regulated. Thus, we speculate that miR-27b is involved in regulating the process of apoptosis in PK-15 cells. In this study we demonstrated that the over-expression of miR-27b led to the inhibition of TGEV-induced apoptosis, reduction of Bax protein level, and decrease of caspase-3 and -9 activities. Conversely, silencing of miR-27b by miR-27b inhibitors enhanced apoptosis via up-regulating Bax expression and promoting the activities of caspase-3 and -9 in TGEV-infected cells. Subsequently, the runt-related transcription factor 1 (RUNX1) is a candidate target of miR-27b predicted by bioinformatics search. We further identified that the miR-27b directly bound to the 3' UTR of RUNX1 mRNA and suppressed RUNX1 expression, which indicates RUNX1 is the direct target gene of miR-27b. The over-expression of RUNX1 increased apoptosis and knockdown RUNX1blocked apoptosis of viral-infected cells via regulating Bax expression and the activities of caspase-3 and -9. Our data reveal that miR-27b may repress the mitochondrial pathway of apoptosis by targeting RUNX1, indicating that TGEV may induce apoptosis via down-regulating miR-27b and that miR-27b may act as a target for therapeutic intervention.
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Xiaomin
authors: X
authors: Zhao
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Xiangjun
authors: X
authors: Song
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Xiaoyuan
authors: X
authors: Bai
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Naijiao
authors: N
authors: Fei
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Yong
authors: Y
authors: Huang
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Zhimin
authors: Z
authors: Zhao
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Qian
authors: Q
authors: Du
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Hongling
authors: H
authors: Zhang
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Liang
authors: L
authors: Zhang
authors: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors: Dewen
authors: D
authors: Tong
keywords: Apoptosis; RUNX1; Transmissible gastroenteritis virus; miR-27b