title: Docosahexaenoic acid attenuates LPS-stimulated inflammatory response by regulating the PPARγ/NF-κB pathways in primary bovine mammary epithelial cells.
abstract: BACKGROUND
  Docosahexaenoic acid (DHA) is a major dietary n-3 polyunsaturated fatty acid (n-3 PUFA) in fish oil, and has been reported to possess a number of biological properties, such as anti-inflammatory, antitumor and immune-regulatory properties. However, whether DHA exert anti-inflammatory effect on lipopolysaccharide (LPS)-induced mastitis remains unclear. In this study, we investigate the effect and underlying mechanisms of the effects of DHA on LPS-stimulated primary bovine mammary epithelial cells (bMEC).
  
  
  METHODS
  The experiment was divided into six groups as followed: control group, GW9662+LPS+DHA (100μM) group, LPS and LPS+DHA (25, 50 and 100μM) groups. bMEC were treated with DHA for 3h before LPS (200μg/ml) stimulation, and incubated with the PPARγ inhibitor GW9662 for 12h before DHA treatment. The mRNA levels of TNF-α, IL-6 and IL-1β were measured by quantitative real-time PCR (qRT-PCR). Western blot was employed for measuring the transcriptional activity of NF-κB and PPARγ.
  
  
  RESULTS
  Our results showed that DHA pretreatment significantly decreased the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in bMEC stimulated with LPS. Besides, DHA suppressed the phosphorylation of nuclear transcription factor-kappaB (NF-κB) p65 and degradation inhibitor of NF-κBα (IκBα) in NF-κB signal pathway, and activated proliferator activated receptor gamma (PPARγ). But, all those effects were obviously abolished by addition of GW9662, a specific inhibitor of PPARγ.
  
  
  CONCLUSIONS
  In conclusion, these results indicated that DHA may attenuate LPS-stimulated inflammatory response in bMEC by suppressing NF-κB activation through a mechanism partly dependent on PPARγ activation.
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Xuexiu
authors.initials: X
authors.lastname: He
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Weijian
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Mingyu
authors.initials: M
authors.lastname: Shi
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Xichen
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China. Electronic address: gong_pengtao@126.com.
authors.forename: Pengtao
authors.initials: P
authors.lastname: Gong
mesh_terms: D000818:Animals; D002417:Cattle; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007249:Inflammation / Q000378:metabolism / Q000662:veterinary; D008070:Lipopolysaccharides / Q000633:toxicity*; D008321:Mammary Glands, Animal / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D047495:PPAR gamma; D012333:RNA, Messenger; D004281:Docosahexaenoic Acids
keywords: DHA; Mastitis; NF-κB; PPARγ; bMEC