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Objective To investigate the effects of methionine restriction(MR)on macrophages in lipopolysaccharide(LPS)-induced acute lung injury(ALI)and to explore the underlying mechanism.Methods According to the random number table method,36 male C57BL/6J mice(6~8 weeks old,23±2 g)were divided into 3 groups with 12 mice in each group:the sham group,the LPS group and the LPS+MR group.HE staining and pathological scoring of lung injury were performed in lung tissues.The expression of LPS-binding protein(LBP)and Toll-like receptor-4(TLR4)was detected by RT-qPCR and Western blotting.Macrophage-colony stimulating factor(M-CSF),granulocyte-macrophage-colony stimulating factor(GM-CSF)and chemokine C-C motif ligand 3(CCL3)which are all macrophage-associated chemokines were analyzed by immunohistochemistry.Results Compared with the sham group,the pathological score of lung injury in the LPS group was significantly increased(P<0.01);The mRNA and protein expression levels of LBP and TLR4 were significantly increased;The number of positive cells of CD11b,F4/80,M-CSF,GM-CSF and CCL3 were significantly increased(P<0.01).MR significantly improved LPS-induced ALI,and decreased the pathological score of lung injury(P<0.01);The mRNA and protein expression levels of LBP and TLR4 were decreased;Compared with the LPS group,the number of positive cells of CD11 b,F4/80,M-CSF,GM-CSF and CCL3 were reduced in the LPS+MR group(P<0.01).Conclusion MR could attenuate LPS-induced ALI by inhibiting the expression of macrophage chemokines and preventing infiltration and activation of macrophage to lungs.
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Objective To establish the model of serum-caused damage to pulmonary microvascular endothelial cells (PMVECs) of mice with renal ischemia-reperfusion (I/R) injury.Methods Mice PMVECs were cultured to measure the standard trans-endothelial electrical resistance (TER) in the monolayer of PMVECs.When PMVECs were cultured and arranged in compact monolayer and TER was achieved,they were divided into 4 groups (n =3 each) using a random number table:serum of normal mice group (NS group) and different concentrations (5%,10% and 20%) of serum of mice with renal I/R injury groups (IRS5 group,IRS10group and IRS20 group).The PMVECs were cultured for 1 h in the serum-free endothelial culture medium.The 0.8 and 0.2 ml culture medium containing 20% serum of normal mice were then added to the upper and lower chambers,respectively,in group NS.The 0.8 and 0.2 ml culture medium containing 5%,10% and 20% serum of mice with renal I/R injury were then added to the upper and lower chambers in IRS5,IRS10 and IRS20 groups,respectively.100 μg/ml FITC-BSA 100 μl was added to the upper chamber in the four groups.At 3,6,9,12,15,18,21 and 24 h of incubation,the PMVEC monolayer permeability (apparent permeability coefficient,Pa) was detected.Results Compared with NS group,the Pa was significantly increased at 12 and 15 h of incubation in IRS5 group,and the Pa was increased at 6-24 h of incubation in IRS10 and IRS20 groups.Compared with IRS5 group,the Pa at 21 and 24 h in IRS10 group and at 9-24 h in IRS20 group were significantly increased.Conclusion Both 10% and 20% serum of mice with renal I/R injury can successfully establish the model of damage to PMVECs,and 20% serum causes a more severe damage.
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Objective To evaluate the role of Src kinase in liver injury in endotoxemic mice.Methods Forty-eight female BABL/c mice,aged 3-4 months,weighing 15-20 g,were randomly divided into 3 groups (n =16 each) using a random number table:control group (C group),endotoxemia group (lipopolysaccharide (LPS) group) and Src kinase inhibitor PP2 group (PP2 group).Endotoxemia was induced by intraperitoneal LPS 20 mg/kg in LPS and PP2 groups,while the equal volume of PBS was given in group C.In PP2 group,PP2 1 mg/kg was injected intraperitoneally at 2 h after LPS administration.At 6 h after LPS or PBS injection,8 mice in each group were chosen,and blood samples were collected from the abdominal aorta for determination of the serum levels of alkaline phosphatase (ALP).The mice were then sacrificed and livers were removed for determination of nuclear factor E2-related factor 2 (Nrf2) level,superoxide dismutase (SOD) activity,malondialdehyde (MDA) content and myeloperoxidase (MPO) activity in liver tissues.The other 8 mice in each group were sacrificed at 24 h after LPS or PBS injection,and the livers were harvested for examination of pathological changes.Results Compared with C group,the serum levels of ALP and MDA content and MPO activity in liver tissues were significantly increased,and SOD activity and Nrf2 levels in liver tissues were decreased in LPS and PP2 groups.Compared with LPS group,the serum levels of ALP and MDA content and MPO activity in liver tissues were significantly decreased,and SOD activity and Nrf2 levels in liver tissues were increased in PP2 group.The pathological changes of liver tissues were significantly attenuated in PP2 group as compared with LPS group.Conclusion Src kinase is involved in endotoxemia-induced liver injury in mice.
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Objective To evaluate the effect of the serum of rats with hepato-pulmonary syndrome (HPS) on the expression of caveolin-1 and VE-cadherin in pulmonary microvascular endothelial cells (PMVECs).Methods Among the 40 healthy Sprague-Dawley rats,aged 3-4 months,weighing 220-250 g,20 rats were taken randomly for establishment the model of HPS which was produced by chronic ligation of the common bile duct,and the left 20 rats served as sham operation group.Primary PMVECs were harvested from healthy adult Sprague-Dawley rats and inoculated in ECM culture medium or on 96-well culture plate.The PMVECs of 4th-9th generation were randomly divided into 2 groups (n =36 each):control group (group C) and HPS group.In group C,the serum obtained from normal rats in sham operation group was added to PMVECs,while the serum obtained from rats with HPS was added in HPS group.The final concentration of serum was 10%.After being incubated for 12,24 and 36 h (T1-3),the expression of caveolin-1 and VE-cadherin in PMVECs was detected by Western blot,and the PMVEC adhesion rate and proliferation were determined by CKK-8 method.Results Compared with group C,the expression of caveolin-1 and VE-cadherin was significantly down-regulated,the cell adhesion rate was decreased,and the proliferation of PMVECs was enhanced in HPS group.Conclusion The serum of rats with HPS induces weakened PMVEC contact inhibition through down-regulating caveolin-1 and VE-cadherin expression.
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Nuclear factor-E2-related factor 2(Nrf2)is a member of C′n′C transcription factor family.It is an important transcrip-tion factor for regulation of cellular redox status and can be seen in all kinds of tissues .Recent studies have demonstrated that rapid deg-radation of Nrf2 after gene-induced antioxidative stress is as important as transcription and activation of Nrf 2 and the nuclear export of Nrf2 is a prerequisite for rapid degradation of Nrf2 in the cytosol.This review focuses on the mechanism of nuclear export of Nrf 2.