Astragalus polysaccharides attenuate PCV2 infection by inhibiting endoplasmic reticulum stress in vivo and in vitro

Sci Rep. 2017 Jan 10:7:40440. doi: 10.1038/srep40440.

Abstract

This study explored the effects of Astragalus polysaccharide (APS) on porcine circovirus type 2 (PCV2) infections and its mechanism in vivo and vitro. First, fifty 2-week-old mice were randomly divided into five groups: a group without PCV2 infection and groups with PCV2 infections at 0, 100, 200 or 400 mg/kg APS treatments. The trial lasted for 28 days. The results showed that APS treatments at 200 and 400 mg/kg reduced the pathological injury of tissues, inhibited PCV2 infection and decreased glucose-regulated protein 78 (GRP78) and GADD153/CHOP gene mRNA and protein expression significantly (P < 0.05). Second, a study on endoplasmic reticulum stress mechanism was carried out in PK15 cells. APS treatments at 15 and 45 μg/mL significantly reduced PCV2 infection and GRP78 mRNA and protein expression (P < 0.05). Tunicamycin supplementation increased GRP78 mRNA and protein expression and significantly attenuated the APS-induced inhibition of PCV2 infection (P < 0.05). Tauroursodeoxycholic acid supplementation decreased GRP78 mRNA and protein expression and significantly inhibited PCV2 infection (P < 0.05). In addition, fifty 2-week-old mice were randomly divided into five groups: Con, PCV2, APS + PCV2, TM + PCV2 and TM + APS + PCV2. The results were similar to those in PK15 cells. Taken together, it could be concluded that APS suppresses PCV2 infection by inhibiting endoplasmic reticulum stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astragalus Plant / chemistry*
  • Cell Line
  • Circoviridae Infections / drug therapy*
  • Circoviridae Infections / pathology
  • Circoviridae Infections / virology*
  • Circovirus / drug effects
  • Circovirus / physiology*
  • Endoplasmic Reticulum Chaperone BiP
  • Endoplasmic Reticulum Stress / drug effects*
  • Mice
  • Oxidative Stress / drug effects
  • Phytotherapy
  • Polysaccharides / pharmacology
  • Polysaccharides / therapeutic use*
  • Swine
  • Taurochenodeoxycholic Acid / pharmacology
  • Tunicamycin / pharmacology
  • Virus Replication / drug effects

Substances

  • Endoplasmic Reticulum Chaperone BiP
  • Hspa5 protein, mouse
  • Polysaccharides
  • Tunicamycin
  • Taurochenodeoxycholic Acid
  • ursodoxicoltaurine