RESUMO
Objective To evaluate the effect of ambroxol on p38 mitogen-activated protein kinase pathway in mice with sepsis-induced lung injury.Methods Sixty male C57BL/6 mice were equally and randomly divided into 3 groups (n=20 each) using a random number table:sham operation group (group S),sepsis-induced lung injury group (group CLP),and sepsis-induced lung injury + ambroxol group (group AMB).Sespsis was produced by cecal ligation and puncture(CLP).Ambroxol 50 mg/kg preconditioning was injected intraperitoneally for 3 days in group AMB,while the equal volume of normal saline instead was given in S and VILI groups.The arterial blood gas was detected 24 h after CLP.Then the mice were sacrificed and broncho-alveolar lavage fluid (BALF) was collected for determination of the concentrations of total protein,interleukin-1β (IL-1β),tumor necrosis factor-α (TNF-α),IL-6 and intercellular adhesion molecule-1 (ICAM-1).The lung tissues were taken for determination of wet to dry lung weight ratio (W/D ratio),expression of p-p38 MAPK,IL-1β mRNA,TNF-α mRNA,IL-6 mRNA and ICAM-1 mRNA,and for examination of the pathological changes which were scored.Results Compared with group S,partial pressure of oxygen in arterial blood(PaO2) was decreased (P＜0.05),and W/D ratio,lung injury score,concentrations of total protein,IL-1β,TNF-α,IL-6 and ICAM-1 in BALF,and expression of p-p38 MAPK,IL-1β,TNF-α,IL-6 and ICAM-1 mRNA were significantly increased in CLP group (P＜0.05).Compared with group CLP,PaO2 was increased (P＜0.05),W/D ratio,lung injury score,concentrations of total protein,IL-1β,TNF-α,IL-6 and ICAM-1 in BALF,and expression of p-p38 MAPK,IL-1β,TNF-α,IL-6 and ICAM-1 mRNA were decreased in group AMB (P＜0.05).Conclusion Ambroxol can attenuate sepsis-induced lung injury probably through inhibiting p38 mitogen-activated protein kinase pathway in mice.
RESUMO
Objective To observe the expression of axon guidance cues Slit2 and Robo4 in lung tissue of rat with acute lung injury (ALI) and explore the function of Slit2 and Robo4 in ALI.Methods Forty-eight Sprague-Dawley rats were randomly (random number) divided into control group (n =24) and ALl group (n =24).ALI model was reproduced by cecum ligation and puncture (CLP).The control group only experienced a simulated operation without CLP.Both groups were further divided into 3 subgroups with 8 rats in each subgroup:12 h,24 h,and 48 h subgroups.artery blood gas analysis,lung tissue wet/dry weight (W/D) ratio,lung histopathologic changes,pulmonary microvascular permeability were observed.The serum tumor nocrosis factor-α (TNF-α) was measured with enzyme linked immunosorbent assay (ELISA).The expression of Slit2 and Robo4 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR).The expression of Slit2 and Robo4 protein in lung tissues was assessed by immunohistochemistry.Date were analyzed by one-way ANOVA with SPSS version 13.0 software.Statistical significance was established at a P value of less than 0.05.Results Compared with the control group,in ALI rats at different time points,partial pressure of oxygen in arterial blood (PaO2) decreased significantly,lung W/D weight ratio and pulmonary microvascular permeability,the serum TNF-α increased significantly (all P ＜ 0.05),histopathology of lung revealed signs of injury.The expression of Slit2 mRNA in lung tissues was decreased markedly after CLP compared with control group [(0.56±0.13) vs.(0.87±0.05),F=41.39,P＜0.05,(0.42±0.10) vs.(0.85±0.07),F=93.54,P＜0.05,(0.26±0.08) vs.(0.89 ±0.09),F=227.05,P＜0.05].but there were no significant difference in expression of Robo4 mRNA in lung tissue between ALI group and control group [(0.86±0.07) vs.(0.83±0.05),F=0.695,P＞0.05,(0.82±0.05) vs.(0.89±0.08),F=2.061,P ＞ 0.05,(0.86 ± 0.08) vs.(0.86 ± 0.05),F =0.035,P ＞ 0.05].Immunohistochemistry study showed Slit2 protein was mainly expressed on the extracellular surface of vascular endothelial cells,while lung epithelial cell nuclei and endochylema.Robo4 protein was only expressed on the extracellular surface of vascular endothelial cells.Compared with the control group,expression of Slit2 protein in lung tissue in ALI group decreased markedly [(0.37 ± 0.05) vs.(0.45 ± 0.07),F =6.82,P ＜ 0.05,(0.32±0.06) vs.(0.47±0.09),F=23.54,P＜0.05,(0.28±0.07) vs.(0.46±0.06),F=28.01,P ＜ 0.05].As good as RT-PCR,there were no significant difference in expression of Robo4 protein in lung tissue between two groups [(0.53±0.04) vs.(0.52±0.05),F=0.155,P＞0.05,(0.53± 0.09) vs.(0.50±0.05),F=0.498,P＞0.05,(0.55±0.06) vs.(0.56±0.07),F=0.073,P ＞ 0.05].Conclusions Lung tissues of control group rats express Slit2 and Robo4.The decreased Slit2 mRNA and protein expressions in the lung tissue of rat with ALI caused by CLP may be associated with the occurrence of ALI.