College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
Sci Rep. 2017 Jan 10;7:40440. doi: 10.1038/srep40440.
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.
本研究探讨了黄芪多糖（APS）对猪圆环病毒 2 型（PCV2）感染的影响及其在体内和体外的作用机制。首先，将 50 只 2 周龄的小鼠随机分为五组：一组无 PCV2 感染，其余四组分别给予 100、200 或 400mg/kg APS 处理后感染 PCV2。试验持续 28 天。结果表明，200 和 400mg/kg 的 APS 处理可减轻组织的病理损伤，抑制 PCV2 感染，并显著降低葡萄糖调节蛋白 78（GRP78）和 GADD153/CHOP 基因 mRNA 和蛋白表达（P<0.05）。其次，在 PK15 细胞中进行了内质网应激机制的研究。15 和 45μg/mL 的 APS 处理可显著降低 PCV2 感染和 GRP78mRNA 和蛋白表达（P<0.05）。添加衣霉素可增加 GRP78mRNA 和蛋白表达，并显著减弱 APS 诱导的对 PCV2 感染的抑制作用（P<0.05）。牛磺熊脱氧胆酸（Tauroursodeoxycholic acid）的添加可降低 GRP78mRNA 和蛋白表达，并显著抑制 PCV2 感染（P<0.05）。此外，将 50 只 2 周龄的小鼠随机分为五组：Con、PCV2、APS+PCV2、TM+PCV2 和 TM+APS+PCV2。结果与 PK15 细胞相似。综上所述，APS 通过抑制内质网应激来抑制 PCV2 感染。
