Taurine attenuates lipopolysaccharide-induced disfunction in mouse mammary epithelial cells

The intent of this study was to evaluate the active defense reaction of mouse mammary epithelial cells and the cytoprotective and anti-inflammatory properties of taurine to lipopolysaccharide (LPS)-induced disfunction in mouse mammary epithelial cells. (1) Primary cultured mouse mammary epithelial cells were stimulated with LPS for 24 h (final concentration=0, 5, 10, 20 μg/mL). Western blotting demonstrated a significant decrease in the secretion of β-casein in the 20 μg/mL LPS treatment group (P<0.05), while nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), lactoferrin (LF) and N-acetyl-β-D-glucosaminidase (NAGase) were all significantly increased following LPS treatment (P<0.01). Furthermore, cell survival was significantly inhibited after treatment with 20 μg/mL LPS; however, neither 5 μg/mL nor 10 μg/mL LPS had any effect on cell survival. Therefore, a level of 10 μg/mL LPS was selected to test the protective effect of taurine on mouse mammary epithelial cells. (2) Primary cultured mouse mammary epithelial cells were treated with 0, 5, 15 or 45 mmol/L taurine for 3 h, followed by 10 μg/mL LPS for 24 h. Taurine significantly attenuated the LPS-induced increase in NAGase activity, NO concentrations and the level of TNF-α, IL-1β, IL-6 and LF. Taurine at 45 mmol/L markedly increased β-casein secretion in response to LPS-induced disfunction. This study demonstrated that the addition of taurine to a culture medium significantly inhibited the LPS-induced release of inflammatory factors and increased β-casein secretion from mammary epithelial cells, thereby providing a possible explanation for the protective effect proposed for taurine in the prevention of LPS-induced disfunction in mammary epithelial cells.