Activation of the Nrf2-ARE pathway improves the phagocytosis of alveolar macrophages under the cigarette smoke extract

Abstract

Objective To explore whether the Nrf2-ARE pathway activators, sulforaphane and terbutyl hydroquinone, can repair the phagocytosis and antioxidant stress ability of alveolar macrophages after cigarette smoke stimulation. Methods The experiment was divided into four groups: the control group, the cigarette smoke extract group, thesulforaphane group and the ter-butyl hydroquinone group.We use the flow cytometry and confocal microscopy to observe and analyze the difference among the groups of phagocytosis and reactive oxygen of alveolar macrophages.Furthermorewe observe the expression of Nrf2 nucleoprotein between the drugs group and non drugs group after intervened by 16 hours by using Western blot. Results Compared with the blank group, the phagocytosis function of alveolar macrophages stimulated by cigarette smoke extract was significantly decreased (P<0.05). The effect of 2.5 μmol/L sulforaphane and 20 μmol/L t-butyl hydroquinone could significantly improve the phagocytosis of alveolar macrophage(P<0.05)and reduce the intracellular reactive oxygen species (P<0.05). Western blotting confirmed that after 16 h intervention, sulforaphaneand t-butylhydroquinonecanpromote alveolar macrophages Nrf2 nuclear protein expression via activatingthe Nrf2-ARE pathway (P<0.05). Under the action of cigarette smoke extract, we have found that the phagocytosis of alveolar macrophage and the expression of Nrf2 nucleoprotein was positively correlated (r=0.93, P<0.05). The intracellular reactive oxygen species and the expression of Nrf2 nucleoprotein was negatively correlated (r=-0.942, P<0.05). The phagocytosis of alveolar macrophage and the intracellular reactive oxygen species is negatively correlated (r=-0.883, P<0.05). Conclusions Nrf2-ARE pathway activatorscan improve the phagocytosis of alveolar macrophages caused by cigarette smoke extract and have protective effects on antioxidant stress. Key words: Sulforaphane; Tert-butyl hydroquinone; Alveolar macrophages; Nrf2-ARE pathway; Oxidative stress