The role of HMGB1 in BMSC transplantation for treating MODS in rats

The effect of bone marrow mesenchymal stem cells (BMSCs) in treatment for multiple organ dysfunction syndrome (MODS) remains unknown and the mechanism is still unclear. Therefore, the goal of this study is to investigate the effects of intracellular high mobility group box 1 protein (HMGB1) on BMSCs treating for MODS. The rats were given 15% blood loss plus 1 mg/kg lipopolysaccharide (LPS) via lower extremity superficial venous, then randomly allocated into four groups: sham group, MODS group, MODS plus BMSC group, MODS plus ethyl pyruvate (EP) group, MODS plus BMSCs plus EP group. Twenty-four hours later, rats in groups were sacrificed and then the blood and tissues were collected to evaluate the changes of tissue histopathology, cell apoptosis, inflammation level and organ function. The HGMB1 expression was monitored by RT-qPCR and Western blot. The expression of RAGE/TLR2/TLR4 and NF-kappa B at the protein levels was also assessed. BMSCs and/or EP exhibits an outstanding protective effect against LPS-induced histopathological injury by improving cell apoptosis, inflammatory response and the organ dysfunction but no effect on BMSC homing to the injury site. Moreover, BMSCs and/or EP inhibited LPS-induced upregulation of HMGB1, RAGE, TLR2 and TLR4 expression at protein levels and compromised p65 phosphorylation in the rat model of MODS. These findings suggest that HMGB1 is involved in BMSC treatment for MODS, through regulation of the TLR2, TLR4-mediated NF-kappa B signal pathway. It suggests that HMGB1 is an attractive potential target for the development of new therapeutic strategies for MODS.