Lactobacillus Delbrueckii Regulates Intestinal Inflammation In Weaned Piglets By Regulating Endoplasmic Reticulum Stress Piglets

In this experiment,intrapulmonary injection of lipopolysaccharide(LPS)was used to induceintestinal inflammation model in weaned piglets.By measuring serum inflammatory cytokine levels,intestinal histopathological score,intestinal epithelial cell apoptosis status and endoparasitic reticulum stress-related genes expression level,we aimed to study the mechanism of Lactobacillus deliberates(LD)relieving intestinal inflammation in weaned piglets,focusing on its regulation of endoparasitic reticulum stress.36 healthy ternary miscellaneous weaned piglets(males)with an average body weight of about 7 kg were randomly selected into three groups,namely control group,LPS group and Lactobacillus deliberates group.Each group had 6 replicates with 2 pigs per replicate.The piglets in the control group and the LPS group were fed with a basic diet,and the diet of the Lactobacillus deliberates group was supplemented with 0.2% Lactobacillus deliberates preparation.The pre-feeding period was 3d and the test period was 28 d.On the 29 th day of the experiment,piglets in the LPS group and the Lactobacillus deliberates group were intraperitoneally injected with 100 μg / kg body weight LPS solution(prepared with normal saline),and the control piglets were injected with the same amount of normal saline as the other two groups.On the 29 th day,one pig was randomly selected from each replication.The pig was slaghtered after collecting blood from the precaval vein.The mucosa and segements of different sections of intesitine were collected for the following test..The results showed that:1)The Lactobacillus deliberates influenced serum inflammatory cytokines in LPS stimulated weaned piglets.Compared with the control group,the content of serum proinflammatory cytokines IL-1β,IL-6,IL-8,IL-12 and TNF-α in piglets of the LPS gourp were significantly increased(P <0.05).The concentration of anti-inflammatory cytokine IL-10 was significantly reduced in LPS group comparing the control group.The IL-1β,IL-6and IL-12 concentrations in the Lactobacillus deliberates group were reduced in varying degrees(P <0.05)comparing the control group.However,the levels of IL-4,IFN-γ,and TGF-β were similar among the three groups(P> 0.05).2)The Lactobacillus deliberates had effects on the intestinal tissue damage score of LPS stimulated weaned piglets.The injury score of jejunum and ileum tissue in the LPS group was significantly higher than that in the control group(P <0.01),but significantly lower than that in the Lactobacillus deliberates group.While the injury score of jejunum and ileum in Lactobacillus deliberates group was still significantly higher than the control group(P <0.01).3)The Lactobacillus deliberates affected the infiltration of inflammatory cells in the intestine of LPS stiulated weaned piglets.Compared with the control group,the contents of MPO and Mac2 in the mucosa of jejunum and ileum in the LPS group were significantly increased(P <0.01).The content of MPO and Mac2 in the mucosa of jejunum and ileum in the Lactobacillus deliberates group was significantly lower than that of LPS group(P <0.01),but significantly higher than that of control group(P < 0.01)except that the content of Mac2 in the mucosa of ileum.4)The effect of Lactobacillus deliberates on the apoptosis of intestinal epithelial cells of weaned piglets with LPS immune stress were significant.Compared with the control group,the apoptosis rates of jejunum and ileum cells in the LPS group and the Lactobacillus deliberates group were significantly increased(P <0.01).And the apoptosis rate of jejunum and ileum cells in the Lactobacillus deliberates group was significantly reduced compared with the LPS group(P <0.01).5)Lactobacillus delbrueckii had some effects on the intestinal endoplasmic reticulum stress and apoptosis-related gene m RNA expression levels of the LPS stimulated weaned piglet.Compared with the control group,LPS significantly increased endoplasmic reticulum stress-related gene GRP78,PERK and ATF6 m RNA expression in ileal tissue(P <0.05).PERK and ATF6 m RNA expression in the Lactobacillus delbrueckii group was significantly lower than that in the LPS group(P <0.05),and GRP78 in the Lactobacillus delbrueckii group was trended to decrease comparing to than that in the LPS group.Howeer,the endoparasitic reticulum stress-related genes detected in jejunum tissues were not significantly different among the three groups(P> 0.05).Among the apoptosis-related genes,the expression of BAX,caspase3 and CHOP m RNA in jejunum and ileum of the LPS group was significantly increased(P <0.05)or trended to increased(P <0.10)compared with that of the control group.The expression of CHOP in the jejunum tissue,caspase3 and CHOP m RNA in ileum tissue in the Lactobacillus deliberates group was decreased comparing to that in the LPS group..The ileum Bcl-2 m RNA expression in the LPS group was significantly lower than that in the control group and the Lactobacillus deliberates group(P<0.05),but there were no difference between the Lactobacillus deliberates group and the control group.Meanwhile,the jejunum Bcl-2 m RNA expression in the three groups were not significantly different..6)L.deuterium had influenced on the intestinal inflammation and endoparasitic reticulum stress-related proteins of LPS immune stress weaned piglets.Compared with the control group,the transformation of NF-κB in jejunum and ileum cells in the LPS group was significantly increased.However,the NF-κB nuclear transformation in the Lactobacillus deliberates group was lower than that in the LPS group.In addition,compared with the control group,the LPS significantly increased the expression of endoparasitic reticulum stress-related proteins GRP78,p-IRE1α in jejunum tissue and GRP78,p-IRE1α and IRE1αin ileum tissue(P <0.05).However,the content of p-IRE1α protein in jejunum and ileum tissues and GRP78 in ileum tissues of Lactobacillus deliberates group were reduced in varying degrees compared with the LPS group(P <0.05).In summary,the addition of Lactobacillus delbrueckii in the diet can alleviate endoplasmic reticulum stress and apoptosis of intestinal epithelial cells,and reduce intestinal inflammatory damage induced by LPS.The IRE1α-NF-κB signaling pathway may be involved in Regulation.