ABSTRACT
Objective:To investigate the role and possible pathogenesis of high mobility group protein B1 (HMGB1) in lipopolysaccharide (LPS)-induced acute lung injury/acute respiratory distress syndrome (ALI/ARDS).Methods:① In vivo, 24 SPFC57BL/6 male mice were randomly divided into normal control group, ALI/ARDS model group, ethyl pyruvate (EP) treatment group and EP control group, with 6 mice in each group. The ALI/ARDS model was established by intraperitoneal injection of 20 mg/kg LPS. Mice in normal control group and EP control group were intraperitoneally injected with the same amount of sterile normal saline. Then, mice in the EP treatment group and EP control group were intraperitoneally injected with 40 mg/kg HMGB1 inhibitor EP. After 6 hours, the mice were sacrificed and lung tissues were collected. The expressions of heparan sulfate (HS), syndecans-1 (SDC-1), heparanase (HPA) and matrix metalloproteinases-9 (MMP-9) in lung tissues were detected by immunofluorescence technique. Orbital blood of mice was collected and serum was extracted to detect the content of HMGB1 by enzyme linked immunosorbent assay (ELISA). ② In vitro, human umbilical vein endothelial cells (HUVECs) were randomly divided into 6 groups: normal control group, HUVECs damage group (treated with 1 mg/L LPS for 6 hours), HMGB1 group (treated with 1 μmol/L recombinant HMGB1 for 6 hours), HMGB1+EP group (treated with recombinant HMGB1 for 1 hour and then added 1 μmol/L EP for 6 hours), LPS+EP group (treated with LPS for 1 hour and then added 1 μmol/L EP for 6 hours), EP group (treated with 1 μmol/L EP for 6 hours). The expressions of HS, SDC-1, HPA and MMP-9 in endothelial cells were detected by immunofluorescence technique. Results:① In vivo, light microscopy showed that the alveolar space was thickened after LPS stimulation, and there were a large number of inflammatory cells infiltrating in the alveolar space. Compared with ALI/ARDS model group, the expressions of HS and SDC-1 in lung tissue of EP treatment group were significantly increased [HS (fluorescence intensity): 0.80±0.20 vs. 0.53±0.02, SDC-1 (fluorescence intensity): 0.72±0.02 vs. 0.51±0.01, both P < 0.05], and the expressions of HPA and MMP-9 were significantly decreased [HPA (fluorescence intensity): 2.36±0.05 vs. 3.00±0.04, MMP-9 (fluorescence intensity): 2.55±0.13 vs. 3.26±0.05, both P < 0.05]; there were no significant changes of the above indexes in EP control group. Compared with ALI/ARDS model group, the content of serum HMGB1 in EP treatment group decreased significantly (μg/L: 131.88±16.67 vs. 341.13±22.47, P < 0.05); there was no significant change in the EP control group. ② In vitro, compared with HMGB1 group, the expressions of HS and SDC-1 in HMGB1+EP group were significantly higher [HS (fluorescence intensity): 0.83±0.07 vs. 0.56±0.03, SDC-1 (fluorescence intensity): 0.80±0.01 vs. 0.61±0.01, both P < 0.05], and the expressions of HPA and MMP-9 were significantly lower [HPA (fluorescence intensity): 1.30±0.02 vs. 2.29±0.05, MMP-9 (fluorescence intensity): 1.55±0.04 vs. 2.50±0.06, both P < 0.05]; the expression of HS, SDC-1, HPA and MMP-9 had no significant changes in EP group. Conclusion:HMGB1 participates in LPS-induced injury of endothelial cell glycocalyx, leading to increased lung permeability, and inhibition of HMGB1 can alleviate lung injury.
ABSTRACT
Objective To investigate the combined biological effects of low dose radiation,carbon monoxide,benzene and noise on rats.Methods Sixteen male SD rats were randomly divided into experiment group and control group.The experiment group was exposed to carbon monoxide,benzene,low dose radiation and noise daily,the control group was in common environment.Peripheral blood,organ index,and marrow DNA content were detected.Two-dimensional electrophoresis (2-DE) was performed on serum protein analysis.Differential expressed proteins were identified by a matrix assisted laser desorption/ionization time of flight mass spectrometry (MAIDI-TOF-MS).Results Compared to control group,the liver index,spleen index,thymus index,leukocytes,platelets count,and marrow DNA content of the experiment group were decreased significantly (t =2.732,4.141,3.053,2.211,2.668,11.592,P ＜0.05).12 altered proteins were detected and through identification,3 proteins were definite in terms of serum amyloid A-4 protein (SAA4),trichoplein keratin filament-binding protein (TCHP) and tubulin alpha-4A chain (TUBA4A).Conclusions The hematopoietic system and immune system of rats are damaged significantly with the changes of several serum protein expressions by the combined exposure of low dose radiation,carbon monoxide,benzene and noise.This study may provide new information for the mechanism of the combination effects.