title: Ochratoxin A promotes porcine circovirus type 2 replication in vitro and in vivo.
abstract: Ochratoxin A (OTA), a worldwide mycotoxin found in food and feeds, is a potent nephrotoxin in animals and humans. Porcine circovirus-associated disease (PCVAD), including porcine dermatitis and nephropathy syndrome, is a worldwide swine disease. To date, little is known concerning the relationship between OTA and porcine circovirus type 2 (PCV2), the primary causative agent of PCVAD. The effects of OTA on PCV2 replication and their mechanisms were investigated in vitro and in vivo. The results in vitro showed that low doses of OTA significantly increased PCV2 DNA copies and the number of infected cells. Maximum effects were observed at 0.05 μg/ml OTA. The results in vivo showed that PCV2 replication was significantly increased in serum and tissues of pigs fed 75 μg/kg OTA compared with the control group and pigs fed 150 μg/kg OTA. In addition, low doses of OTA significantly depleted reduced glutathione and mRNA expression of NF-E2-related factor 2 and γ-glutamylcysteine synthetase; increased reactive oxygen species, oxidants, and malondialdehyde; and induced p38 and ERK1/2 phosphorylation in PK15 cells. Adding N-acetyl-L-cysteine reversed the changes induced by OTA. Knockdown of p38 and ERK1/2 by their respective specific siRNAs or inhibition of p38 and ERK1/2 phosphorylation by their respective inhibitors (SB203580 and U0126) eliminated the increase in PCV2 replication induced by OTA. These data indicate that low doses of OTA promoted PCV2 replication in vitro and in vivo via the oxidative stress-mediated p38/ERK1/2 MAPK signaling pathway. This suggests that low doses of OTA are potentially harmful to animals, as they enhance virus replication, and partly explains why the morbidity and severity of PCVAD vary significantly in different pig farms.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Gan
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Zheqian
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: John
authors.initials: J
authors.lastname: Hesketh
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Xue
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Xingxiang
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Hao
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Patience
authors.initials: P
authors.lastname: Cole Ezea
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
authors.forename: Fahmida
authors.initials: F
authors.lastname: Parveen
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China. Electronic address: khhuang@njau.edu.cn.
authors.forename: Kehe
authors.initials: K
authors.lastname: Huang
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002460:Cell Line; D017925:Circovirus / Q000187:drug effects* / Q000472:pathogenicity / Q000502:physiology; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology / Q000821:virology; D005786:Gene Expression Regulation; D005921:Glomerulonephritis / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology / Q000821:virology; D005721:Glutamate-Cysteine Ligase / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000037:antagonists & inhibitors / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000473:pathology / Q000821:virology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D050983:NF-E2 Transcription Factor / Q000235:genetics / Q000378:metabolism; D009793:Ochratoxins / Q000037:antagonists & inhibitors / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D053570:Porcine Postweaning Multisystemic Wasting Syndrome / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology / Q000821:virology; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000819:agonists / Q000378:metabolism; D013552:Swine; D019562:Viral Load / Q000187:drug effects*; D014779:Virus Replication / Q000187:drug effects*; D014886:Weaning; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004279:DNA, Viral; D050983:NF-E2 Transcription Factor; D009793:Ochratoxins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C025589:ochratoxin A; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D000111:Acetylcysteine
keywords: Free radicals; Ochratoxin A; Oxidative stress; Porcine circovirus type 2; Signaling pathway