【Animal Modeling】-Study on the safety and efficacy of human umbilical cord mesenchymal stem cells in the treatment of acute lung injury in mice

  Objective To investigate the safety and efficacy of human umbilical cord mesenchymal stem cells (HUC-MSCs) in the treatment of lipopolysaccharide (LPS)-induced acute lung injury in mice.

  Methods The safety of HUC-MSCs was evaluated by tumorigenicity test, in vitro hemolysis test and acute toxicity test. Taking 6-8-week-old C57BL/6 male mice as experimental subjects, an acute lung injury model was established by intranasal or intraperitoneal injection of LPS. HUC-MSCs treatment was given 6 h after modeling, and the treatment groups were divided into: tail vein injection group (5×107 cells/kg) and atomization group (HUC-MSCs conditioned medium). The pathological results of the lung tissue of the mice in each group were observed 96 hours after modeling, and the count and classification of inflammatory cells in the bronchoalveolar lavage fluid (BALF) of the mice were observed by Wright-Giemsa staining.

  Results HUC-MSCs showed no tumorigenicity, no obvious hemolytic reaction, and no acute toxicity. Compared with the control group, both modeling methods showed a certain degree of lung injury, and the McGuigan score of lung tissue pathological section showed that the lung injury caused by intraperitoneal injection of LPS was more serious than that in the nasal drop group. Compared with the model group, the degree of lung tissue damage in the treatment group was significantly reduced, and the treatment effect in the tail vein injection group was better than that in the nebulization group, and the number of macrophages in the BALF was significantly increased (P<0.001).

  Conclusion The acute lung injury model of mice induced by intraperitoneal injection of LPS is better than that of intranasal administration. Tail vein injection of human umbilical cord mesenchymal stem cells can effectively treat acute lung injury in mice, and aerosol administration of HUC-MSCs conditioned medium can alleviate lung inflammation in mice.