Xuexiu He1, Weijian Liu1, Mingyu Shi1, Zhengtao Yang1, Xichen Zhang1, Pengtao Gong2. 1. College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China. 2. College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China. Electronic address: gong_pengtao@126.com.
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. CONCLUSION: 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.
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. CONCLUSION: 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.