title: Sodium tanshinone IIA sulfonate inhibits porcine reproductive and respiratory syndrome virus via suppressing N gene expression and blocking virus-induced apoptosis.
abstract: BACKGROUND
  Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant economic loss in the swine industry. Currently, there is no effective way to prevent PRRSV infection. Sodium tanshinone IIA sulfonate (STS), a natural compound derived from Salvia miltiorrhiza, was shown to possess anti-PRRSV activity, but the underlying mechanisms remain unclear. The objective of this study was to investigate the effect of STS on PRRSV-induced cell apoptosis and PRRSV N protein expression pattern.
  
  
  METHODS
  Relative quantification real-time PCR was used to evaluate the inhibition of STS on N gene expression. Simultaneously indirect immunofluorescence assay (IFA) and western blot were used to assess the effect on N protein expression. Apoptosis was analysed using fluorescence microscope with an annexin V-EGFP kit. The effect of STS on caspase-3 cleaving was assessed by western blot.
  
  
  RESULTS
  Our results showed that STS could inhibit viral N gene expression at both the messenger RNA stage and at the protein level in PRRSV-infected cells in a dose-dependent manner. In addition, STS could also rescue PRRSV-induced apoptosis.
  
  
  CONCLUSIONS
  Our data suggest that STS may serve as a base compound for developing more effective drugs against PRRSV infection.
authors.affiliation: College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Sun
authors.forename: E
authors.initials: E
authors.lastname: Li
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Junxing
authors.initials: J
authors.lastname: Zhao
authors.forename: Shaoyu
authors.initials: S
authors.lastname: Wang
authors.forename: Junping
authors.initials: J
authors.lastname: He
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Bai
authors.forename: Hongquan
authors.initials: H
authors.lastname: Li
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D019590:Nucleocapsid Proteins / Q000235:genetics* / Q000378:metabolism; D010616:Phenanthrenes / Q000494:pharmacology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000187:drug effects* / Q000502:physiology*; D013552:Swine
chemical_list: D000998:Antiviral Agents; D019590:Nucleocapsid Proteins; D010616:Phenanthrenes; C024894:tanshinone II A sodium sulfonate; D053148:Caspase 3