Mechanism of microglia cell activation and differentiation induced by lipopolysaccharide / 中华神经医学杂志

ABSTRACT

Objective To observe the effect and molecular mechanism of lipopolysaccharide (LPS) on activation and differentiation of microglia (MG) cells. Methods Routinely in vitro cultured BV2 microglia cells were divided into control group and LPS group BV2 microglia cells in the LPS group were treated with 200 ng/mL LPS; cells in the control group were added the same amount of medium. Six h after treatment, real-time quantitative (qRT)-PCR and enzyme-linked immunosorbent assay (ELISA) were used to detect the inflammatory factors, interleukin (IL)-1β and tumor necrosis factor (TNF)-α mRNA and protein expressions in supernatant of cell culture medium. The iNOS, CD32, Arg1 and CD206 mRNA and protein expressions were detected by qRT-PCR and immunofluorescence, respectively. The mRNA and protein expressions of Notch1, Hes1 and Hes5 were detected by qRT-PCR and Western blotting. Results After LPS stimulation, BV2 microglia cells were activated and the morphological changes were observed. The IL-1β and TNF-α protein and mRNA expressions in the LPS group were significantly increased as compared with those in the control group (P<0.05). The iNOS and CD32 protein and mRNA expressions in the LPS group were significantly increased as compared with those in the control group (P<0.05). The Arg1 and CD206 mRNA and protein expressions showed no significant differences between the two groups (P>0.05). The Notch1 and Hes1 mRNA and protein expressions in the LPS group were significantly increased as compared with those in the control group (P<0.05), while no significant differences on Hes5 mRNA and protein expressions were noted between the two groups (P>0.05). Conclusion LPS activates MG cells, which may regulate the differentiation of MG cells into M1 through Notch signaling pathway and promote inflammatory response; therefore, Notch signaling pathway may be a target for regulating MG cells differentiation and reducing inflammatory damage.