Effect Of Bone Marrow Mesenchymal Stem Cells On The Repaire Of Intestinal Mucosa In A Mouse Model Of Ulcerative Colitis

Objective:The research is to investigate the repair effect of bone marrow mesenchymal stem cells(BMSCs)on injured intestinal mucosa in a mouse model of ulcerative colitis.Methods:BALB/C female mice were randomly divided into normal control group,experimental group 1(DSS+PBS)and experimental group 2(DSS+BMSCs).The normal control group was regularly fed,while the other two groups drank aqueous solution of 4% dextran sodium sulfate(DSS)every day.After drinking water for 8 days,the control groups and experimental groups were injected with PBS and BMSCs respectively,then 5 mice in each group were sacrificed on day 2、5、9、12 and 16 after injection.Colon tissues were harvested.Disease activity index(DAI)was scored according to the clinical manifestations of mice to evaluate the mice disease activity.HE staining was used to detect intestinal mucosal injury and inflammatory factors infiltration.Immunohistochemistry,ELISA and qRT-PCR were used to detect the expression of c-Mesenchymal epithelial transition factor(c-Met),epidermal growth factor receptor(EGFR),proliferating cell nuclear antigen(PCNA)and Hepatocyte growth factor(HGF),hepatocyte growth factor Hepatocyte growth factor activator(HGFA),tumor necrosis factor(TNF)-α,interferon(IFN)-γ,as well as the tight junction proteins in colon tissues.RESULTS: The DAI scores and colon histological damage scores of both experimental group 1 and experimental group 2 were higher than those of the normal control group,and the scores of the experimental group 2 on the 9th and 12 th day of stem cell intervention were lower than the experimental group 1(P<0.05).The expression of c-Met,EGFR and PCNA in the colon tissue of the experimental group 1 was significantly lower than that of the normal control group and the experimental group 2(P<0.05).BMSCs could affect the expression of tight junction proteins in the colonic mucosal tissue.Except for day 2 and day 9,the expression of HGF in the experimental group 2 was significantly higher than that in the experimental group 1(P<0.05).The expression of HGFA decreased firstly and then increased in the experimental group 1,but there was no obvious regular differences among the three groups.IFN-γ in the experimental group 2 was significantly lower than that in the experimental group 1(P<0.05),while TNF-α was lower than the experimental group 1 only in the later stage of the experiment.Conclusion:Our study suggested that BMSCs can promote the repair of intestinal mucosal injury in a mouse model of ulcerative colitis induced by DSS.