Toll-like receptor-4, but not toll-like receptor-2 mediates secretion of tumour necrosis factor α and interleukin-8 in lipopolysaccharide-stimulated mouse mammary epithelial cells

Abstract

Mammary epithelial cells (MECs) from Kunming mice were isolated and stimulated in vitro with 10 μg/mL of Escherichia coli lipopolysaccharide (LPS). The release of tumour necrosis factor α (TNF-α) and interleukin-8 (IL-8) into culture supernatants was measured by ELISA. Furthermore, blocking experiments with Toll-like receptor 2 (TLR2) and TLR4 antibodies were performed to verify whether cytokine secretion depended on LPS-induced activation of TLR2 or TLR4. The results revealed that LPS-stimulated mouse MECs significantly secreted TNF-α and IL-8. Blocking of the TLR4 pathway inhibited the secretion of TNF-α and IL-8, while inhibition of LPS-induced TNF-α and IL-8 production was not observed when TLR2 was blocked. Thus, TLR4 can mediate the LPS-induced expression of cytokines such as TNF-α and IL-8 in mouse MECs.

Chinese herbal Jin-Ying-Tang attenuates the inflammatory response by inhibiting the activation of TLR4/MyD88/TRAF-6/NIK pathway at the mRNA level in LPS-stimulated mouse mammary epithelial cells

“…This was found by Pareek et al (23) and Wellnitz and Kerr (33). In our previous laboratory study (8), we found that mouse MECs can respond to the presence of LPS (10 μg/mL) and significantly up-regulate the release of TNF-α and IL-6. Using the LPS-stimulated infection model, we investigated the effect of JYT addition to the LPS-stimulated culture on production of TNF-α and IL-6.…”

“…The procedure for primary culture of MECs has been previously described (8). In brief, mammary tissue was isolated from midpregnancy mice, and epithelial cells were obtained after mixed protease digestion of the tissue.…”