Effect Of Resolvin D1 On Experimental Colitis Mice By Regu Lating Macrophage Autophagy

Background:Inflammatory bowel disease(IBD)is a common chronic gastrointestinal disease.Inflammatory immune disorders are closely related to the occurrence and development of inflammatory bowel disease.As an important part of the intestinal mucosal immune system,macrophages are involved in the pathogenesis of IBD.Autophagy is an intracellular degradation system and immune defense mechanism.When autophagy is defective,the number of macrophages increases and the immune response is overactivated.Resolvin D1(RvD1)is produced by neutrophils or macrophages.It is an endogenous anti-inflammatory lipid molecule derived from omega-3 fatty acids.Studies have found that RvD1 can reduce the body's inflammatory response,but the mechanism by which RvD1 affects colitis is unclear.Therefore,this study is to explore the related effects of progesterone D1 on colitis inflammation and its possible mechanism.Objective:To investigate the protective effect of Resolvin D1 on experimental colitis and its possible mechanism.Methods: Mice were random Ly divided into normal control group,RvD1 control group,model control group and RvD1 administration group.The colitis model was constructed by drinking 5% DSS solution freely and RvD1(50 mg/kg)was intraperitoneally injected into mice on 2th day,4th day and 6th day.DAI score was measured during the experiment.At the end of the experiment,the peritoneal macrophages and the colon tissues were collected.Histological index(HI),myeloperoxidase(MPO),cytokine levels were measured and the structure of autophagosome in peritoneal macrophage was observed by electron microscope.The expression levels of related genes such as Beclin-1,p62,LC3-? and pro-IL-1? were detected and analyzed by real-time PCR and Western blot.ResuLts:Compared with the model control group,the DAI score,HI score,MPO activity level and the level of proinflammatory cytokine were decreased in the RvD1 administration group(P<0.05).The expression levels of Beclin-1,LAMP-2,LC3-?/LC3-? in peritoneal macrophages increased,and the expression levels of i NOS,IL-1? and p62 decreased(P<0.05).Conclusion:RvD1 has a protective effect on experimental colitis,and the mechanism may be involved in the regu Lation of impaired autophagy in macrophages.