title: β-Glucan modulates the lipopolysaccharide-induced innate immune response in rat mammary epithelial cells.
abstract: Mastitis, caused by mammary pathogenic bacteria which are frequent implications of Escherichia coli, is an important disease affecting women and dairy animals worldwide. The β-glucan binding of dectin-1 can induce its own intracellular signaling and can mediate a variety of cellular responses. This work was to investigate the effect of β-glucan on the lipopolysaccharide (LPS)-induced inﬂammatory response and related innate immune signaling in primary rat mammary epithelial cells. Cells were treated with serum-free medium added with a DMSO solution containing β-glucans at concentrations of 0, 1, 5, 25 μmol/L for 12h, and then exposed to 10 μg/mL LPS for 40 min. Moreover, cells were pretreated with BAY 11-7082 to inhibit NF-κB and then successively exposed to 5 μmol/L β-glucan, 10 μg/mL LPS, 5 μmol/L β-glucan and 10 μg/mL LPS, according to the specific experimental design. Normal control cultures contained an equal volume of DMSO, which was collected at the same time. After incubating rat mammary epithelial cells for 40 min with 10 μg/mL LPS, TLR4, MyD88 and NF-κB expression all increased (P<0.05), as did the secretion of TNF-α and IL-1β (P<0.05), but IκB and β-casein expression both decreased (P<0.05). Treatment with different concentrations of β-glucan for 12h activated Dectin1/Syk, which subsequently suppressed TLR4, MyD88 and NF-κB expression and TNF-α and IL-1β secretion. However, it restored the IκB and β-casein expression that had been induced by the 40 min incubation with 10 μg/mL LPS. Pretreatment with BAY 11-7082 at 10 µmol/L for 2h partially prevented NF-κB induction by LPS, but the presence of β-glucan prevented this inactivation. BAY 11-7082 could not simultaneously inhibit LPS induction of TLR4, MyD88 and β-glucan activation of Dectin1/Syk in rat mammary epithelial cells. These findings demonstrated that β-glucan activation of Dectin1/Syk attenuated LPS induction of TLR4/MyD88/NF-κB and inhibited the LPS-induced inflammation factors in mammary epithelial cells, thereby providing a possibly protective effect of β-glucan in the prevention of LPS-induced dysfunction in mammary epithelial cells.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.forename: Haitian
authors.initials: H
authors.lastname: Ma
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Miao
authors.forename: Guoqing
authors.initials: G
authors.lastname: Huang
authors.forename: Mingqing
authors.initials: M
authors.lastname: Tong
authors.forename: Sixiang
authors.initials: S
authors.lastname: Zou
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology; D005260:Female; D007113:Immunity, Innate; D053583:Interleukin-1beta / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology; D008321:Mammary Glands, Animal / Q000166:cytology; D008413:Mastitis / Q000188:drug therapy* / Q000276:immunology; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D061251:Primary Cell Culture; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013450:Sulfones / Q000494:pharmacology; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D047071:beta-Glucans / Q000008:administration & dosage*; D000099181:Dectin-1
chemical_list: D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D037181:Lectins, C-Type; D008070:Lipopolysaccharides; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D009570:Nitriles; D013450:Sulfones; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D047071:beta-Glucans; D000099181:Dectin-1; C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile