Study on the expression of spleen tyrosine kinase and inflammatory factors stimulated by lipopolysaccharide in human mammary epithelial cells

Objective To investigate the expression levels of spleen tyrosine kinase(SYK) induced by LPS in human mammary epithelial cells, and its effects on the gene expression of inflammatory cytokine.

Methods The inflammatory response in human mammary epithelial cells were induced by LPS to establish the acute lactation mastitis cell model.The cell proliferation activity was detected by CCK-8 assay.The real-time quantitative PCR was used to obtain the optimal stimulation time and concentration of SYK, and detected the expression levels of related inflammatory cytokine genes.The expression levels of SYK genes in human mammary epithelial cells before and after LPS stimulation were detected by immunofluorescence.

Results The results of CCK-8 showed that there was no significant change in the proliferative activity of human mammary epithelial cells stimulated by 25 μg/mL LPS for 1 h(P>0.05).The results of real-time fluorescence quantitative PCR showed that the expression of SYK gene in mammary epithelial cells was the most significant after 25 μg/mL LPS stimulation for 1 h(P < 0.05).After LPS stimulation, the expression levels of interleukin(IL)-1β, IL-6, IL-8, tumor necrosis factor α and NLRP3 increased(P < 0.05), and the expression levels of IL-1β, IL-6, tumor necrosis factor α and NLRP3 decreased after the SYK gene knockdown by siRNA(P < 0.05).

Conclusions Inhibition of SYK gene can reduce the release of inflammatory factors in LPS-induced mastitis cell models, and has a certain protective effect on mammary epithelial cells.