Effect Of Taurine On LPS-induced Intestinal Autophagy In Broilers

The intestine is the most important organ against external pathogens.When it is inflamed,it releases a large number of inflammatory factors and induces cells to initiate autophagy.Excessive autophagy can cause autophagic death of cells,endangering the health of broilers,and Will affect broiler production.Studies have shown that taurine can inhibit the secretion of inflammatory factors and also regulate cell autophagy,but can taurine protect the intestinal tract by inhibiting the excessive secretion of inflammatory factors and thereby weakening the cell's excessive autophagy? The specific mechanism of injury is not clear.In this study,a model of intestinal hyperautophagy was induced by intraperitoneal injection of lipopolysaccharide(LPS)in broilers.Taurine was added to the diet to test the role of taurine on the regulation of intestinal autophagy in broilers.Acid provides theoretical basis for the application of preventing intestinal inflammation and protecting intestinal function.The experiment selected 120 white feather broilers at 1 day of age and divided them into 4 treatments.Each treatment was divided into 6 repetitions and 5 repetitions each.The blank control group(C)was fed with basic diets on 28 and 29 days.At 30 o'clock on the 30 th day,saline was injected intraperitoneally;the taurine control group(T)added 0.3% taurine to the basic diet,and then injected intraperitoneally for three consecutive days;the model group(M)was fed the basic diet LPS(1mg / kg.BW)was injected intraperitoneally for three consecutive days;the taurine prevention group(MT)added 0.3% taurine to the basic diet,and LPS(1mg / kg.BW)was injected intraperitoneally for three consecutive days.The main findings are as follows:1)Immune organ index: There is no significant difference in the immune organ index between the four groups(p> 0.05);2)Jejunum morphology: The jejunum villi of the model group was broken,causing severe damage to the morphology.The intestinal structure of the taurine control group was less damaged,although the villi,layers and crypts were clear and complete despite the damage;3)Serum biochemical indicators: Compared with the blank control group,the expression levels of IL-1?,IL-6,IL-8,IL-8,IL-12,TNF-?,TNF-?,and TNF-? in the model group were significantly increased(p <0.01),compared with the model group,the taurine prevention group can significantly down-regulate(p <0.01)the expression level of inflammatory factors(p> 0.05);4)LPS / TLR4 / NF-?B pathway: Compared with the blank control group,the expression levels of TLR4 and NF-?B genes and proteins were significantly increased in the model group(p <0.05).The taurine prevention group was compared with the model group.Down-regulated the expression levels of TLR4 and NF-?B genes and proteins(p <0.05);5)Autophagy structure of jejunum tissue: In the model group,organelles were severely damaged,mitochondria were broken,and endoplasmic reticulum and Golgi morphology were damaged.The mitochondria of the taurine prevention group showed a large number of autophagy structures,forming typical autophagosomes and relatively complete organelle structures.6)m RNA expression of autophagy marker genes: Compared with the blank control group,the expression levels of autophagy markers Beclin-1 m RNA and LC3? m RNA were significantly increased(p <0.05),and the relative expression levels of LC3?m RNA were decreased(p> 0.05).The taurine prevention group down-regulated the expression of Beclin-1 and LC3? m RNA(p <0.05)and up-regulated the expression of LC3?m RNA compared with the model group(p> 0.05);7)Screening of autophagy pathways and verification of PI3 k / AKT / m TOR pathway: RNA-seq technology was used to find differential genes related to the occurrence of autophagy to create a gene set,and the autophagy pathway PI3 k / AKT / m TOR was screened for further research Compared with the blank control group,the relative expression levels of PI3 K m RNA,AKT m RNA,and m TOR m RNA in the model group were significantly reduced(p <0.05),and the taurine prevention group was up-regulated compared with the model group.Expressed the expression of this pathway(p <0.05).8)m RNA expression of intestinal mechanical barrier-related genes: Compared with the blank control group,the relative expression levels of ZO-1 m RNA,Claudin-1 m RNA,and Occludin m RNA in the intestinal mechanical barrier were reduced in the model group(p <0.05).The taurine prevention group increased the expression of these three genes compared with the model group(p <0.05);9)m RNA expression of intestinal transporter-related genes: Compared with the blank control group,the relative expression levels of the genes related to nutrient transporter Pep T1 m RNA,GLUT2 m RNA,and apo B m RNA were reduced(p <0.05).Taurine prevention Compared with the model group,the expression of these three genes was up-regulated in the group(p <0.05).In summary,the addition of taurine in the feed can resist the damage caused by excessive autophagy induced by lipopolysaccharide,and can also improve the damaged intestinal cells,strengthen the intestinal barrier function,and maintain the normal function of nutrient absorption..