[Effect of adipose-derived mesenchymal stem cells and liraglutide on acute lung injury].

Objective: To explore the protective effect of human adipose-derived mesenchymal stem cells (AD-MSCs) and liraglutide on lipopolysaccharide (LPS) -induced acute lung injury (ALI) . Methods: AD-MSCs were cultured in vitro and randomly divided into 3 groups: control group, LPS group (30 mg/L) , and LPS (30 mg/L) +liraglutide (10 nM) group. MTT assay was used to detect the proliferation of AD-MSCs at 6, 24, 48 and 72 h. Annexin V-FITC / PI double staining flow cytometry was used to detect the apoptosis of the cells. Western blot was used to detect the expression of apoptotic proteins cleaved caspase-3, Bax and Bcl-2 at 72 h in vitro. For the in vivo experiment, 60 male SPF BALB/c mice were randomly divided into 5 groups: control group, ALI group, ALI+AD-MSCs group, ALI+Liraglutide group, and ALI+AD-MSCs+Lraglutide group. The mice were sacrificed on day 2 and day 7 after LPS treatment. HE staining was used to examine the pathological changes of the lungs of mice, and the scores of lung injury were measured. The lung tissues of mice were examined by immunohistochemistry, and the expression of the marker protein Nanog of mesenchymal stem cells was observed. BALF was collected, and the number of BALF neutrophils was counted by Rayleigh Giemsa staining. The wet/dry specific gravity of mouse lung tissue was recorded. Results: The apoptosis of AD-MSCs stimulated by LPS was significantly higher than that of the control group (P<0.05) , and the proliferation of AD-MSCs at 6, 24, 48 and 72 h was significantly lower than that of the control group (all P<0.05) . The addition of Liraglutide reduced the apoptosis of AD-MSCs (P<0.05) , and promoted the proliferation of AD-MSC at 6, 24, 48 and 72 h. Compared with the control group, in the 2 d and 7 d model groups, the lung injury pathology of ALI group had lung injury, increased number of neutrophils in BALF (65.63±1.34 vs 1.74±0.17, 51.67±1.35 vs 1.55±0.13) ×10(4)/ml (all P<0.05) , and increased W/D of lung tissues. The expression level of Nanog protein was low in the 7 d model group. Compared with the ALI group, in 2 d and 7 d model groups, the ALI+AD-MSCs group, the ALI+liraglutide group, and the ALI+AD-MSCs+liraglutide group showed reduced lung injury pathology, and the number of neutrophils was decreased, (37.04±1.23, 29.17±0.68) ×10(4) / ml (all P<0.05) in the ALI+AD -MSCs group, (39.58±1.67, 35.42±0.25) ×10(4) / ml in the ALI+Liraglutide group (all P<0.05) and (28.54±0.37, 21.46±0.89) ×10(4)/ml (all P<0.05) in the ALI+AD-MSCs+Liraglutide group. Lung tissue W/D in the ALI+AD-MSCs group, ALI+Liraglutide group and ALI+AD-MSCs+Liraglutide group showed the same trend. Nanog protein expression increased in the 7 d model group. Conclusions: AD-MSCs play a protective role in acute lung injury in mice under the synergistic effect of liraglutide.