Effect Of Selective Estrogen - β Receptor Agonist On Macrophage Immunoregulation And Its Molecular Mechanism

Objectives:Estrogen conducts biological effect through combination with estrogen receptor, and estrogen receptor beta (ERβ) is one of the important receptor. ERβ agonists is thought to play an important role in estrogen-dependent inflammatory disease. It has sure effect in treatment of some estrogen-related inflammatory diseases, such as endometriosis and inflammatory bowel disease. Although the anti-inflammatory role of ERβ agonists is unclear, ERβ agonists as an anti-inflammatory agent is becoming a research focus. In this study, a macrophage inflammatory model, induced by lipopolysaccharide (LPS), was designed to investigate the anti-inflammatory effects of selective ERβ agonists Diarylpropionitrile (DPN). We studied the effects of DPN on LPS-induced inflammatory cytokines released by macrophages and cell migration of macrophages, as well as nuclear factor-κB (NF-κB) in inflammatory pathways.Methods:Expression of ERβ protein was determined in mouse peritoneal macrophages (MPMs) and mouse macrophage cell line RAW264.7with Western Blot technique. Applications of LPS to induce MPMs inflammatory model and macrophage cell line RAW264.7inflammatory model. ERβ agonist DPN was exposed to these two groups. The expressions of IL-1β, TNF-a and RANTES in these cells were determined with ELISA. Subsequently, in LPS-induced RAW264.7exposed to DPN, NF-κB inflammatory pathways of p65protein accumulated in the nuclear was evaluated by immuno fluorescence method, and p65protein phosphorylation level and degradation of IκB were detected by Western Blot.Results:ERβ was expressed in both MPMs and mouse macrophage cell line RAW264.7. DPN was able to significantly decrease the expression of RANTES in macrophage inflammatory model, but had no effect on TNF-a expression (p>0.05). Pretreatment the LPS-induced MPMs with DPN showed no evident of enhance IL-1β secretion, but high concentration of DPN had a marked enhancement of IL-1β secretion in RAW264.7. DPN inhibited RANTES-induced migration of RAW264.7, as well as nuclear translocation of p65and the phosphorylation of p65by inhibiting the degradation of IκB, which lead to prohibition of activated translation of NF-κB.Conclusions:ERβ agonist DPN down regulates the expression of RANTES and further inhibits the migration of macrophages, which might lead to the alleviating of inflammation. The anti-inflammatory effect of DPN is possibly mediated via repressing of NF-κB signaling pathway.