Improvement Of Intestinal Immune Dysfunction Induced By LPS In Broilers By Yeast Selenium

Selenium(Se)is an important trace element and plays an important role in the growth and development of humans and animals.The human body consumes selenium mainly from fish,eggs,meat and milk.In most areas,selenium in meat is the main source of intake.In China's low-selenium areas,due to the low selenium content in the soil,animals and plants cannot absorb enough selenium from it,leading to a series of diseases such as white muscle disease,decreased reproductive function,encephalomalacia,and neurodegenerative diseases.Adding selenium to animal feed can increase the selenium intake in animal diets,and humans can increase the selenium content in their bodies by eating the edible tissues of selenium-rich animals.Therefore,the production of selenium-enriched animals can increase the selenium intake from human diet.Selenium is divided into organic selenium and inorganic selenium.Generally speaking,the absorption and metabolism and bioavailability of organic selenium are higher than that of inorganic selenium,while the toxicity is less than that of inorganic selenium.This article studies the effects of yeast selenium on the intestines of broilers.In this test,the effects of selenium on the intestinal tract of broilers were revealed by methods such as real-time fluorescence quantitative PCR and Western blotting.Based on the model of control group,0.35 Se,0.5Se,LPS,0.35Se+LPS and 0.5Se+LPS,we observed the changes of intestinal histomorphology,cytokines,antimicrobial peptides,immunoglobulins,heat shock proteins,selenoproteins and related inflammatory factors the m RNA and Western blot were detected.The test results show that:(1)After yeast selenium supplementation,the intestinal epithelium structure of broilers was clear,the length of intestinal villi increased,and the depth of crypt increased.After LPS stimulation,the intestinal histomorphology of broilers changed significantly,and the characteristics of intestinal epithelial inflammation were obvious.The structure of intestinal mucosa is loose,there are a large number of inflammatory cells and lymphocytes in the local area.The pathological changes of intestinal inflammation were most obvious in CON+LPS group.The villi were sparse,the structure of intestinal gland was fuzzy,the chorion was broken,and the central chylous duct was narrowed.The results of light microscopy showed that LPS could damage the intestinal immune function of Broilers and lead to intestinal inflammation.(2)Compared with the control group,the m RNA expression levels of IL-1R,IL-2,IL-4,IL-6,IL-17 and IFN-? in 0.35 Se group and 0.5Se group were not significantly different;the m RNA expression levels of antimicrobial peptides AVBD1,AVBD6,AVBD7,AVBD9,AVBD10 and AVBD12 were significantly increased;the m RNA expression levels of immunoglobulin Ig A,Ig Y and p Ig R were not significantly different,while the m RNA expression levels of IL-1R,IL-2,IL-4,IL-6,IL-17 and IFN-? in CON+LPS group were not significantly different The levels of AVBD1,AVBD6,AVBD7,AVBD9,AVBD10,AVBD12,Ig A,Ig Y and p Ig R decreased significantly.Compared with the CON+LPS group,the m RNA expression level of IL-1R,IL-2,IL-4,IL-6 in the 0.35Se+LPS group and the 0.5Se+LPS group was significantly lower,and the m RNA expression level of IL-17 and IFN-? was significantly higher,among which the expression level of IL-17 in the 0.5Se+LPS group was significantly lower;the expression level of AVBD1,AVBD6,AVBD7,AVBD9,AVBD10 and AVBD12 in the 0.35Se+LPS group was significantly higher Compared with 0.5Se+LPS group,the expression of Ig A,Ig Y,p Ig R m RNA was significantly increased.The results showed that LPS induced intestinal immune system damage in broilers,and yeast could improve the immune system function.(3)Sixteen selenoprotein related genes(DIO3,Gpx1,GPx2,GPx3,GPx4,Sel H,Sel N,Sel O,Sel P1,Sel P2,Sel T,Sel W,Sepx1,Txnrd1)were detected in the intestine of broilers.It was found that the selenoprotein related gene expression in broilers fed with yeast selenium increased significantly,while LPS stimulation decreased the expression level of selenoprotein the intestine.Compared with CON+LPS group,the expression of selenoprotein in 0.35Se+LPS group and 0.5Se+LPS group was significantly increased.(4)Compared with the control group,the m RNA expression level of HSP27,HSP70 and HSP90 in the CON+LPS group was significantly lower,and the m RNA expression level of HSP40 and HSP60 was significantly higher;the m RNA expression level of HSP27,HSP40 and HSP70 in the 0.35 Se group was significantly higher than that in the 0.5Se group,and the m RNA expression level of HSP60 was not significantly different,and the m RNA expression level of HSP90 was significantly lower.Compared with CON+LPS group,HSP27,HSP70 and HSP90 m RNA expression in 0.35Se+LPS group and 0.5Se+LPS group were significantly increased,but HSP40 m RNA expression was not significantly different.HSP60 m RNA expression in 0.35Se+LPS group was significantly increased,while HSP60 m RNA expression in 0.5Se+LPS group was significantly decreased.The protein expression level of HSP60,HSP70 and HSP90 was significantly higher than that of the control group.Therefore,yeast Selenium can improve the immune function of intestine.(5)In addition,compared with the control group,the expression level of COX-2,NF-?B,PGE,TNF-? m RNA in 0.35 Se group and 0.35 Se group was not significantly different,and the expression level of i NOS m RNA was significantly reduced;the expression level of COX-2,NF-?B,PGE,TNF-?,i NOS in CON+LPS group was significantly increased.Compared with CON+LPS group,the expression of COX-2,NF-?B,PGE,TNF-? and i NOS in 0.35Se+LPS group and 0.5Se+LPS group decreased significantly.The results showed that LPS stimulated the intestinal inflammation of broilers,while yeast selenium reduced the intestinal inflammation caused by LPS.In conclusion,LPS stimulates the gut of broilers to damage the immune system,activate a series of inflammatory factors and immune system related factors,which lead to immune system dysfunction.The purpose of this study is to elucidate that yeast selenium can regulate the expression of cytokines,antimicrobial peptides,immunoglobulins,selenoproteins,heat shock proteins and related inflammatory factors by mediating the immune system,enhance the function of intestinal epithelial immune system,and determine that yeast selenium has an effect on LPS induced intestinal immune system dysfunction.