Comparison of therapeutic effects in different ways of bone marrow mesenchymal stromal cells injection in rats with ulcerative colitis

Objective To compare the efficacy of intracardiac injection and intravenous injection of bone marrow mesenchymal stromal cells (BMSCs) in rats with ulcerative colitis (UC) and analyze the therapeutic mechanism. Methods BMSCs from SD male rats were in vitro cultured. The rat model of UC was established by 5% trinitrobenzenesulfonic acid (TNBS)/ethanol enema. Group D was the control group. And 24 hours later, rats of group A were injected with 0.5 ml of BMSCs suspension via the heart (1×10⁶). Rats of group B were injected with 0.5 ml of BMSCs suspension via tail vein (1×10⁶). Rats of group C were injected with equal volume of normal saline via tail vein. Disease activity index (DAI) of rats in every group was observed and calculated. The rats were sacrificed at day 7 after injection. The pathological changes of the colon and the expression of human sex-determining region Y protein (SRY protein), factor associated suicide (FAS), leucine-rich repeat containing g protein coupled receptor 5 (Lgr5) were observed under microscope. Results DAI of group A was lower than that of group B and C (F=90.603, P＜ 0.05) but there were no differences between group A and B. The repairing of injured colon in group A was much better than in group B. The SRY protein could be detected in transplantation group. Compared with the control group, the expression of Fas in group C increased (t=9.494, P＜ 0.05). Compared with group C, the expression of Fas in treatment group decreased. And the expression in group A was lower than in group B. There were significant difference among the three groups (F=38.6, P＜ 0.05). Compared with group C, the expression of LGR-5 in treatment group was significantly increased. And the expression in group A was higher than in group B. There were significant difference among the three groups (F=24.7, P＜ 0.05). Conclusion The efficacy of intracardiac injection of BMSCs is much better than the efficacy of intravenous injection in rats with UC. BMSCs plays a therapeutic role in rats with UC by reducing intestinal cells apoptosis and promoting intestinal stem cell regeneration.