Effect Of Bone Marrow-derived Mesenchymal Stem Cells On The Repair Of Intestinal Barrier Function In Mouse Model Of Ulcerative Colitis

Objective:1、To explore the methods to isolate, culture and identify the bone marrow-derivedmesenchymal stem cells of mice.2、To establish the mouse model of ulcerative colitis.3、To track the transplanted cells by Y chromosome labeling method.4、To study the effect of bone marrow-derived mesenchymal stem cells on the repair ofintestinal barrier function in mouse model of ulcerative colitis.Methods:1、BM-MSCs of male mice were cultured by whole bone marrow adherent method in vitro,and it was identified by morphological characters, adherent properties, surface antigen andmultilineage diffentiation potential. In addition, It’s activity was identified by its growthcurve.2、Female BALB/c mice were free to drink5%dextran sulfate sodium(DSS) to establishUC models, and they were evaluated by the clinical and pathological performance duringthe modeling period.3、The BM-MSCs were transplanted into the mouse model of UC via tail vein, and it wastracked through Y chromosome labeling method.4、After the BM-MSCs were transplanted, at different time points, to detect the level ofD-LAC and DAO in mouse plasma and the number of bacteria in mesenteric lymph nodes,to observe the HE staining and E-cadherin protein expression of colon tissue, so that toevaluate the effect of the BM-MSCs on the repair of intestinal barrier function in mousemodel of UC.Results:1、The mouse BM-MSCs which were obtained by whole bone marrow adherent methodwere a group of spindle cells, just like fibroblast cells. It’s growth pattern was typicalpolarity swirling, and its adherent properties was very good; By flow cytometry, the expression of CD34and CD45were low, but the expression of CD44and CD90were high;After they were induced by osteogenic medium and stained by alizarin red, we can see alot of calcium deposits in its cytoplasm, and after they were induced by adipogenicmedium and stained by oil red O, we can see a lot of red lipid droplets in its cytoplasm. It’sgrowth curve showed a typical “S”type.2、During the modeling period, after drinking5%DSS3-4days, the mice began to emergestool changes and weight loss;5-7days later, all the mice were varying degrees of bloodystools. And the DAI score of these mice increased gradually.7days later, its colonicmucosa appeared multiple erosions and ulcers, and a lot of inflammatory cells infiltrated inits mucosa and submucosa.3、After the BM-MSCs were transplanted into the mice of stem cells transplantation goup3d,7d,14d and21d, we can detect SRY protein-positive cells in its colon tissue.4、After the BM-MSCs were transplanted, compared with the model control group, thelevel of D-LAC and DAO in mouse plasma and the number of bacteria in mesentericlymph nodes of stem cells transplantation goup decreased quickly. The results of colonichistopathology showed that the injury of mucosal and the expression of E-cadherinrecovered faster than the model control group.Conclusion:1、Whole bone marrow adherent method is a simple and reliable method to isolate andculture BM-MSCs, we can get good activity and high purity BM-MSCs by this way.2、The success rate and the repeatability of the mouse model of UC induced by DSS is veryhigh. And the clinical pathology performance and the pathogenesis is similar to people.3、The BM-MSCs can be transplanted into mice successfully via tail vein, and theBM-MSCs which were transplanted into mouse model can survival in colon tissue.4、The BM-MSCs which were transplanted into the mouse model of UC, can improve thepermeability of colon mucosa, promote the repair of intestinal barrier function.