| Because of the special environment of the plateau,people who entering the plateau are prone to gastrointestinal reactions.The available research shows that it may be due to the impaired intestinal barrier function,which will affect the absorption of nutrients and thus lead to weight loss,at the same time,disorders of the intestinal flora,bacterial translocation and endotoxin generation occur in the intestine.Innate immune cells activate and release inflammatory factors,cause local or systemic inflammatory response of the body,serious threat to the health of people who entering the plateau.According to our previous studies,plateau environment can lead to increased expression of multiple inflammatory factors in serum and imbalance of intestinal flora in rats,and the disturbance of intestinal flora is related to the occurrence and development of a variety of diseases.Colon tissue is the main aggregation place of intestinal flora,so whether plateau environment can lead to colon barrier damage and whether the disturbance of intestinal flora is related to colon barrier damage.Studies on this are rarely reported.This project will study the damage effect of plateau environment on the barrier function of colon tissue in mice,explore the correlation between intestinal flora disorder and colonic injury,and explore the protective effect of probiotics on the colon barrier in mice.This project is mainly divided into the following three parts.To explore the inflammatory damage effect of plateau environment on colonic barrier in mice.HE staining was used to observe the pathological injury of colon caused by plateau environment,pimonidazole staining was used to observe the hypoxia of colon tissue under plateau environment,ELISA was used to measure the expression of inflammatory factors in colon tissue,and WB and RT-PCR were used to measure the expression of tight junction protein and inflammation-related proteins.To explore the correlation between colon barrier function injury and intestinal flora disturbance caused by plateau environment.After removing the disturbed intestinal flora and giving the normal intestinal flora in the plain,it was observed whether the colon barrier damage caused by the plateau environment would be reduced.16 S r RNA was used to detect the changes of intestinal flora composition,HE staining was used to observe the changes of colon pathology,and ELISA was used to observe the changes of inflammatory factors.The expression of tight junction protein was determined by WB and RT-PCR.To explore the protective effect of probiotics on the barrier function of colon tissue in mice in plateau environment.HE staining was used to observe the effect of probiotics on the colonic morphology of mice,ELISA was used to measure the changes of inflammatory factors,WB was used to measure the expression of tight junction protein.The experimental results are as follows:(1)Colonic barrier injury in mice caused by high altitude environment.High altitude environment can lead to pathological injury of colon tissue in mice,with increased the level of hypoxia,increased inflammatory factors and decreased tight junction protein expression.High altitude environment exposure for 12 h,24 h and 48 h,the expression of Claudin 1 protein in tissues is downregulated by 9.1%,28.5% and39.6%.Occludin protein expression decreased by 43.5%,69.9% and 39.3%.The expression of ZO-1 protein in tissues was down-regulated,but there was no significant difference.The expressions of NF-κB,HIF-1α and STAT1 increased by 29.72%,33.97%and 18.48%,after 12 h at the plateau.After 24 h of high altitude exposure,the increase was 119.74%,98.66%,and 76.72%.After 48 h of high altitude exposure,the upregulations were 156.39%,154.99% and 148.59%.The results showed that the plateau environment could cause inflammatory damage to the colon barrier in mice and activate inflammatory pathways.(2)There is a correlation between colon barrier inflammation and intestinal flora disturbance in plateau environment.In the pseudo-aseptic model group,the pathological damage was alleviated to a certain extent,and the inflammatory factors such as IFN-γ,IL-6,TNF-α,IL-10,IL-12 and IL-1β were reduced,which were significantly reduced by 23.41%,1.13%,8.05%,6.59%,1.78% and 11.20%,in the 12 h pseudo-aseptic model group.In the plateau 8 day pseudo-sterility group,the expression of tight junction protein was increased,and the protein level was upregulated by 29.73%,163.06% and 42.84%,which were significantly reduced by13.25%,5.78%,8.13%,0.36%,2.56% and 18.26%.m RNA levels were up-regulated184.68,1.61 and 3.07 times.In the fecal bacteria transplantation group,the pathological injury reduction degree of colon tissue was more obvious,and the inflammatory factors were reduced by 21.27%,4.25%,8.04%,4.21%,4.09% and 19.77%.The expression of tight junction protein was increased,and the protein level was increased by 101.91%,236.59% and 104.77%.m RNA levels were up-regulated 449.65,1.21 and 2.61 times.This indicates that barrier inflammation in colon tissue of mice in plateau environment is related to intestinal flora disorder.(3)Administration of tetradectin viable tablets can protect colon tissue damage caused by plateau environment.The expression of IFN-γ,IL-6,TNF-α and IL-1β were decreased after administration of probiotics at both 12 h and 8 d,and probiotics treated intestinal barrier injury.Among them,the 12 h probiotics group significantly decreased by 27.71%,4.99%,7.69% and 18.46%.In addition to IFN-γ,other inflammatory factors of the 8 d probiotics group decreased by 12.64%,11.43% and 20.31%.Tight junction protein expression increased,and compared with the plateau group,Claudin 1,Occludin and ZO-1 in the plateau group increased by 12.85%,128.51% and 215.49%,in the plateau group after 12 hours.Compared with the plateau group after 8 days,In Plateau 8 d probiotics group,Claudin 1,Occludin and ZO-1 increased by 94.23%,127.04% and 41.43%.In conclusion,high altitude environment can affect the tight connection of colon tissue in mice,damage colon barrier function,and increase tissue permeability.This is related to the disorder of intestinal flora,and giving fecal bacteria transplantation or probiotics can significantly improve the damage of colon barrier function in mice in plateau environment.The results suggest that people entering the plateau may need to take probiotics appropriately to adjust the disturbed intestinal flora,reduce gastrointestinal reactions and maintain health. |
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