Modulation Effects Of Liver X Receptors Agonists On Alveolar Macrophage Phagocytosis Of Rats During Acute Lung Injury

Objective: To observe the effect of liver X receptor agonists T0901317on the alveolarmacrophage phagocytosis of Acute Lung Injury, and to explore the effect of liver Xreceptor on acute lung injury and its possible protective mechanism.Methods:60male SD rats were divided randomly into three groups: control group(group N),LPS treatment group (group L) and T0901317+LPS treatment group (group T).group T with liver X receptor agonist T0901317irrigated1week later, then the rats werekilled after intraperitoneal injection of LPS6h. group L and the group N in dimethylsulfoxide irrigated1week later, respectively, intraperitoneal injection of LPS, saline, therats were killed after intraperitoneal injection6h. And then were taken to the lung tissueand observe the changes in general and pathological morphological changes. Finally, Tocollect bronchoalveolar lavage fluid of each group, and to separate and purificate ofalveolar macrophages, MPO staining determinate alveolar macrophages the MPO positivestaining rate, in addition, using purified alveolar macrophages and then measured thephagocytosis percentage of chicken red blood cells and phagocytic index, and theexpression of Mer mRNA and protein in lung tissue were detected by RT-PCR and Westernblot techniques.Results:(1)The general morphology of lung tissue:the group N of lung tissue has a goodelasticity and the density is uniform,smooth Envelope,with pink color; the group L of lungtissue with area bleeding,tissue swelling,uneven color;the group T of lung tissue was swell-ling, but the tissue injury of group T was lighter than group L, no large hemorrhage.(2)Pathological changes of lung tissue: In group N, the lung tissue alveolar wall is thin, clear and completed,no inflammatory cells infiltrated in the alveolar clearance and alveoli-ar spaces,no obvious broken or expansion blood vessels;In group L,the lung tissue was da-maged severe,alveolar wall was ruptured and collapsed,local emphysema or atelectasis,alv-eolar cavity was infiltrated with a large number of red blood cells,inflammatory cell,and e-ven the alveolar space structure disappeared;the lung tissue lesions of group T are lighter t-han the group L,but the arealveolar structure is incomplete,inflammatory cell infiltration c-hanged in the alveolar space.(3)The MPO positive staining rate,percentage of macrophage phagocytic index of group T-alveolar macrophages greater than group L,group N,the results show that group Talveolarmacrophage phagocytic function was stronger than the group L and the group N(P<0.05, a significant different）.(4)Mer mRNA expression and protein levels of group T was significantly higher than the Lgroup and N group,the difference was statistically significant (P<0.05).Conclusion:(1)The liver X receptor agonists T0901317has a significant protectiveeffect on LPS-induced rat acute lung injury.(2)The phagocytic function of alveolarmacrophages was significantly lower on LPS-induced acute lung injury,and liver Xreceptor can significantly enhance the phagocytic function of alveolar macrophages,alsothe Mer gene expression.(3)The protective mechanism of liver X receptor on acute lunginjury may be achieved by enhancing the phagocytic ability of alveolar macrophages andraising Mer gene expression.