Classical swine fever virus NS5A protein localizes to endoplasmic reticulum and induces oxidative stress in vascular endothelial cells.
Classical swine fever virus (CSFV) causes a severe disease of pigs that is characterized by hemorrhage, disseminated intravascular coagulation, and leucopenia. Until now, the role of the nonstructural protein 5A (NS5A) produced by CSFV in the pathogenesis of CSF is not well known. In this study, we investigated the function of CSFV NS5A by examining its role in the induction of oxidative stress and related intracellular events. Stable swine umbilical vein endothelial cell lines expressing CSFV NS5A were established and showed that CSFV NS5A is localized to endoplasmic reticulum and induces oxidative stress associated with enhanced reactive oxygen species production. The expression of NS5A protein exerts different effects on the three major antioxidants. Particularly, it exhibits a significant increase in transcriptional activities of antioxidant proteins thioredoxin and peroxiredoxin-6, but accompanied by a concomitant decrease of antioxidant protein heme oxygenase-1. Further studies showed that cyclooxygenase-2, a pro-inflammatory protein related to oxidative stress, is up-regulated while anti-inflammatory protein peroxisome proliferator-activated receptor-γ, an important mediator in vascular functional regulation, is down-regulated in CSFV NS5A expressing cells. This study suggested that CSFV NS5A plays important roles in the induction of oxidative stress and inflammatory response in vascular endothelial cells. These findings provide novel information on the function of the poorly characterized CSFV NS5A and provide an insight into the mechanism by which CSFV NS5A can alter intracellular events associated with the viral infection.
College of Veterinary Medicine, Northwest A & F University, Yangling, 712100 Shaanxi, China. helei4280546@163.com
Lei
L
He
Yan-Ming
YM
Zhang
Zhi
Z
Lin
Wei-Wei
WW
Li
Jing
J
Wang
He-Lin
HL
Li
D000818:Animals; D002460:Cell Line; D006692:Classical Swine Fever Virus / Q000472:pathogenicity*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000821:virology*; D042783:Endothelial Cells / Q000821:virology*; D020869:Gene Expression Profiling; D051547:Heme Oxygenase-1 / Q000096:biosynthesis; D018384:Oxidative Stress; D047495:PPAR gamma / Q000096:biosynthesis; D054465:Peroxiredoxin VI / Q000096:biosynthesis; D013552:Swine; D013879:Thioredoxins / Q000096:biosynthesis; D017361:Viral Nonstructural Proteins / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism*
D047495:PPAR gamma; D017361:Viral Nonstructural Proteins; D037521:Virulence Factors; D013879:Thioredoxins; D054465:Peroxiredoxin VI; D051547:Heme Oxygenase-1; D051546:Cyclooxygenase 2