RESUMEN
Objective_To investigate the potential effect of bone marrow mesenchymal stem cells ( MSCs) on repai-ring the colon epithelial cell,and on the treatment of rats with ulcerative colitis ( UC) .Methods_Monocytes were purified from bone marrow, amplified and identified as MSCs in vitro.Thirty female Wistar rats were randomly di-vided into 3 groups, the normal control, model and MSCs groups (10 rats/group).The rats in model and MSCs groups were induced colitis with trinitro-benzene-sulfonic acid;The rats in normal control group and model groups were injected with 1mL saline via tail vein, while those in MSCs group with 1 mL MSCs suspension.After two weeks, colon tissue samples were analyzed for histopathology,and the colon tissues were made into serial section for determining the distribution of Y chromosome and CK20 double positive cells,analyzing the mRNA levels of CK20,NF-κB, IL-4 by RT-PCR,and assaying colonic NF-κB protein expression with Westen blot,detecting colon tissues IL-4 content with ELISA.Results_Y chromosome and CK20 double positive cells were found in MSCs transplanted colon tissues.The expression of CK20 increased in the colon tissues of UC rats(P<0.01) and in MSCs group in-creased as compared with model group( P<0.01) .The expression of NF-κB increased in the colon tissues of UC rats (P<0.01), but decreased MSCs group as compared with model group (P<0.01).The expression of IL-4 was decreased in the colon tissues of UC rats ( P<0.01) , while in MSCs group it was increased as compared with model group ( P<0.01) .Conclusions_MSCs may have therapeutic efficacy on colitis in rats through differentiating into colon epithelial cells.