Fig. 7

Recurrent low-grade LPS exposure causes severe mastitis in lactating mice. Lactating mice were treated with LPS (2 or 20 μg/mouse) intraperitoneally for 10 consecutive days after delivery, and then mammary tissues were harvested for determination. A Serum LPS levels from the indicated mice (n = 5). B Representative mammary H&E-stained sections from differently treated mice (scale bar, 50 μm). C Histological scores of the mammary glands from the indicated mice (n = 5). D, E Mammary TNF-α (D), IL-1β (E), and MPO activities (F) in the different groups were determined (n = 5). G Representative western blot images of tight junction and TLR4-cGAS-STING-NF-κB/NLRP3 pathway proteins in the mammary tissues from the indicated groups. The relative intensities of ZO-1, occludin, claudin-3, TLR4, cGAS, STING, p-TBK1, p-IRF3, p-p65, p-IκB, NLRP3, ASC, and IL-1β in the mammary glands (H–T) were determined (n = 3). Data are expressed as the mean ± SD (A, C–F, H–T), and one-way ANOVA was performed followed by Tukey’s test (A, C–F, H–T). *p < 0.05, **p < 0.01, ***p < 0.001 indicate significance