关键词: 灵芝多糖(GLPs), 巨噬细胞, Toll样受体4(TLR4), 核因子-κB(NF-κB), 炎性细胞因子

Abstract: Objective To investigate the inhibitory effects of ganoderma lucidum polysaccharides (GLPs) on toll like receptor 4 (TLR4) signal transduction pathways and inflammatory cytokines regulating mechanism activateby lipopolysaccharide (LPS) in macrophage. Method Macrophage was stimulated with LPS for 16 hours and treated with the GLPs (low dose group 40 µg/mL, mid dose group 80 µg/mL, high dose group 160 µg/mL) for 2 hours simultaneously. In basis of this, the real-time fluorescent quantitative PCR and Western blotting methods were used to respectively detecting mRNA and protein of all groups of TLR4, myeloid differentiation factor 88 (MyD88), nuclear factor-kappa B (NF-κB), tumor necrosis factor receptor-associated factor 6 (TRAF-6), tumor necrosis factor alpha (TNF-α) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). Result (1) The mRNA relative expression were activated of TLR4 and primary element of downstream MyD88 dependent signal transduction pathway in LPS group, such as TLR4, MyD88, NF-κB and TRAF-6, which had significant differences compared with normal group (P<0.05). The GLPs could restrain in a degree the mRNA expression of TLR4, MyD88, NF-κB and TRAF-6 after being interfered in. The TLR4, MyD88 and TRAF-6 mRNA of GLPs-Mid and GLPs-High dose group had significant differences compared with LPS group (P<0.05). The NF-κB mRNA of all GLPs groups had significant differences compared with LPS group (P<0.05). And then, the relative expression of TLR4, MyD88, NF-κB and TRAF-6 protein in each group was consistent with the expression of mRNA. (2) Compared with normal group, the mRNA expression of TNF-α and LOX-1 were significantly increased in LPS group (P<0.05). The GLPs could restrain in a degree the mRNA expression of TNF-α and LOX-1 after being interfered in, which had significant differences compared with LPS group (P<0.05). And then, the expression of TNF-α and LOX-1 protein in each group was consistent with the expression of mRNA. Conclusion It was speculated that GLPs might restrain the expression of TLR4 and primary element of downstream MyD88 dependent signal transduction pathway. It was also illustrated that GLPs might restrain the expression of inflammatory cytokines such as TNF-α and LOX-1.

Key words: Ganoderma lucidum polysaccharides (GLPs), Macrophage, Toll like receptor 4 (TLR4), Nuclear factor-kappa B (NF-кB), Inflammatory cytokines