The Study Of MIR-155 Regulates IL-6,IL-10 And MIP-2expression In Alveolar Macrophages In Acute Lung Injury Induced By Sepsis

Objective:To investigate the effects of MIR-155 on IL-6,IL-10 and MIP-2 of alveolar macrophages in acute lung injury induced by sepsis.Methods:The 15 healthy and cleanC57BL6 male mice of 6-8 weeks(18-20g)were randomly divided into 3 groups,the control,the sepsis and the miR-155 antagomir groups.The cecal ligation and perforation(CLP)were used to prepare the animal model of acute lung injury with sepsis.Six hours after the model was successfully constructed,The pathological changes of left lower lobe were observed under light microscope after HE Dyeing and slicing.The right subpulmonary lobe was used to measure the dry and wet weight ratio.Plasma IL-6,IL-10,MIP-2 were detected by ELISA.Results:The HE staining results showed that alveolar structure destruction,inflammatory cell infiltration,pulmonary interstitial thickening and bleeding were observed in the sepsis and miR-155 antagomir group.They also showed that the ratio of dry and wet weight was significantly lower in the sepsis group than that of the control and miR-155 antagomir group,and the difference was found to be statistically significant(P<0.05).The results of ELISA showed that the level of MIP-2,IL-6 in the plasma of septic group weresignificantly higher than those of the control and the miR-155 antagomir group,and the level of MIP-2 and IL-6 in the plasma of the miR-155 antagomir group were higher than those of the control group(P<0.05).The level of IL-10 in the plasma of the septic group was significantly lower than that of the control and the miR-155 antagomir group,and the level of IL-10 in the plasma of the miR-155 antagomir group was lower than that of the control group(P<0.05)Conclusion:Overexpression of miR-155 in mice with acute lung injury induced by sepsis can promote the release of a large number of anti inflammatory factors and inhibit the expression of anti inflammatory factors in alveolar macrophages,which leads to an imbalance between the pro-inflammatory and anti-inflammatory factors,resulting in an inflammatory reaction.However,miR-155 antagomir can inhibit the expression of miR-155,which can further inhibit the alveolar macrophages to release anti-inflammatory factors IL-6 and chemokine macrophage MIP-2,raise the expression of anti-inflammatory factor IL-10 cells.It further prevents the accumulation of neutrophil and alveolar macrophages,effectively controls the occurrence of lung inflammation,which plays a protective role in lung.