Effect Of Ulinastatin On Th17 And Related Factors In Mice With Acute Lung Injury Induced By Lipopolysaccharide

OBJECTIVE:To study the effects of ulinastatin on Th17 cells,RORγt and IL-17 secreted by lipopolysaccharide(LPS)in acute lung injury induced by airway drip.METHODS:Fifty-four SPF C57BL/6 mice were randomly divided into control group,lipopolysaccharide group and ulinastatin group.They were administered for 2 hours,6 hours and 24 hours respectively,with 6 mice in each group.Blood was collected by eyeball bleeding 2 hours,6 hours and 24 hours after intervention and mice were executed.After hematoxylin-eosin(HE)staining,the pathological changes of lung tissue were observed under light microscopy;the expression of IL-17 protein in lung tissue and around trachea was detected by immunohistochemistry;the content of IL-17 in lung tissue was determined by enzyme-linked immunosorbent assay(ELISA);the expression of IL-17A and RORγt in lung tissue was detected by real-time quantitative PCR;and the expression of IL-17A and RORγt in lung tissue was detected by Western blot assay(WB).The expression of RORYγt was detected by tern Blot,and the percentage of Th17 cells in CD4+T cells in peripheral blood,lung and spleen was detected by flow cytometry.RESULT:1.HE results showed that the lung tissue structure of mice in the control group was basically normal 2,6 and 24 hours after intervention,and the lung tissue injury of mice in the LPS group was gradually aggravated 2,6 and 24 hours after intervention,and the lung injury score was significantly increased,which was higher than that of the control group at the same time.The model of acute lung injury induced by LPS was successfully established.The degree of lung injury and the score of lung injury in Ulinastatin group were significantly lower than those in LPS group at the same time(all P<0.05).2.Immunohistochemical results showed that the expression of IL-17 protein in lung tissue and trachea of mice in the control group was not stained or light yellow at 2h,6h and 24h after intervention;the expression of IL-17 protein in lung tissue and trachea of mice in the LPS group was light brown yellow,brown yellow and brown at 2h,6h and 24h after intervention,and the expression of IL-17 protein in lung tissue and trachea of mice in the Ulinastatin group was higher than that in the LPS group at 2h,6h and 24h after intervention.Shallow.Quantitative analysis:The immunohistochemical staining score of IL-17 protein in LPS group was higher than that in control group,and the immunohistochemical staining score of IL-17 protein in Ulinastatin group was lower than that in LPS group,with statistical significance(all P<0.05).3.ELISA results showed that compared with the control group,the IL-17 content in lung tissue of LPS group increased 2,6 and 24 hours after intervention.Compared with LPS group,the IL-17 content in lung tissue of Ulinastatin group decreased at 2h,6h and 24h after intervention(all P<0.05).4.RT-PCR results showed that compared with the control group,the expression of IL-17 and RORγt in lung tissue of LPS group increased 2,6 and 24 hours after intervention.Compared with lipopolysaccharide group,the expression of IL-17 and RORγt in lung tissue IL-17 and ROR γ t decreased in Ulinastatin group at 2h,6h,6h,24h and 24h after intervention,compared with lipopolysaccharide group,the expression of IL-17 in lung tissue IL-17 was significantly lower(all P<0.05)5Westem blot showed that the expression of ROR Y t protein in lung tissue of LPS group increased 2,6 and 24 hours after intervention compared with control group.Compared with LPS group,ROR γ t protein expression in lung tissue of Ulinastatin group decreased at 2h,6h and 24h after intervention(P<0.05).6.The results of flow cytometry showed that the percentage of-Th17 cells in peripheral blood,lung and spleen tissues in LPS group increased 2,6 and 24 hours after intervention compared with the control group.Compared with LPS group,the percentage of Thl7 cells in peripheral blood,lung tissue and spleen tissue in Ulinastatin group decreased 2,6 and 24 hours after intervention,and the difference was statistically significant(all P<0.05).CONCLUSION:Ulinastatin can reduce the expression of IL-17 and its transcription factor ROR Y t by inhibiting the differentiation of Th17 cells,thereby alleviating the acute lung injury induced by LPS in mice and playing a protective role in acute lung injury.