[Administration of bone marrow mesenchymal stem cells attenuates inflammation of rats with sepsis]

Objective To investigate the therapeutic effects of bone marrow-derived mesenchymal stem cells (BMSCs) in rats with sepsis. Methods Forty-eight Wistar rats were divided into blank group, sham group, model group and treatment group. Sepsis model was made using cecum ligation and puncture (CLP). BMSCs were extracted and cultured to the third generation. The rats in the treatment group received BMSCs through a tail vein and the rats in the model group received an equivalent dose of PBS. The survival rate was recorded in each group 72 hours after operation. Pathological changes of lung tissues were observed by HE staining. The mRNA levels of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), fork head box protein 3 (Foxp3), CC chemokine ligand 2 (CCL2) were tested by quantitative real-time fluorescence PCR. The serum levels of IL-6, IL-17 and TNF-α proteins were detected by ELISA. Results In both blank group and sham group, the survival rate and histological changes of the lungs showed normal; no bacteria were found growing in rats' blood culture; IL-6, IL-17, TNF-α, CCL2, Foxp3 mRNA and IL-6, IL-17, TNF-α protein levels had no significant differences. In the model group, the survival rate of rats was obviously lower than that of the sham group; the pathological changes of the lungs were significant; any amount of enterobacteria were seen growing in rats' blood culture; IL-6, IL-17, TNF-α, CCL2 mRNA and protein expression levels were apparently higher than those of sham group, while Foxp3 mRNA expression level was obviously lower than that of sham group. In the treatment group, the survival rate was significantly higher than that of the model group; the pathological changes of the lung tissues were evidently eased; IL-6, IL-17, TNF-α, CCL2 mRNA and protein expression levels significantly decreased compared with the model group, while Foxp3 mRNA expression level significantly increased compared with the model group. Conclusion BMSCs injection increases the survival rate in rats with sepsis and reduces the levels of inflammatory cytokines.